Annex IV
                                       to
                               Securities Purchase
                                    Agreement


               AMENDED AND RESTATED REGISTRATION RIGHTS AGREEMENT

        THIS AMENDED AND RESTATED  REGISTRATION  RIGHTS  AGREEMENT,  dated as of
November  12,  1997  (this  "Agreement"),  is  made  by  and  between  XYBERNAUT
CORPORATION, a Delaware corporation (the "Company"), and the entity named on the
signature page hereto (the "Initial Investor").

                              W I T N E S S E T H:

        WHEREAS,  the  Company  and the  Initial  Investor  desire  to amend and
restate that certain  Registration  Rights  Agreement to which they are parties;
and

        WHEREAS, upon the terms and subject to the conditions of the Amended and
Restated Securities  Purchase Agreement,  dated as of November 12, 1997, between
the Initial Investor and the Company (the "Securities Purchase Agreement"),  the
Company has agreed to issue and sell to the Initial  Investor up to 3,640 shares
(the "Preferred  Shares") of 4% Series B Convertible  Preferred Stock, par value
$.01 per share,  of the Company,  at an aggregate  purchase price of $3,640,000,
which  Preferred  Stock  (as that term is  defined  in the  Securities  Purchase
Agreement) is convertible  into shares of the Common Stock,  $.01 par value,  of
the  Company  (the  "Conversion  Shares")  upon the  terms  and  subject  to the
conditions of the  Certificate  of  Designations  (as defined in the  Securities
Purchase Agreement);

        WHEREAS,  to induce the  Initial  Investor  to execute  and  deliver the
Securities  Purchase  Agreement,  the  Company  has  agreed to  provide  certain
registration rights under the Securities Act of 1933, as amended,  and the rules
and regulations thereunder, or any similar successor statute (collectively,  the
"Securities Act"), with respect to the Conversion Shares;

        NOW,  THEREFORE,  in  consideration  of  the  premises  and  the  mutual
covenants  contained  herein  and other  good and  valuable  consideration,  the
receipt and  sufficiency of which are hereby  acknowledged,  the Company and the
Initial Investor hereby agree as follows:


1.         Definitions.

        (a) As used in this  Agreement,  the  following  terms  shall  have  the
following meanings:

        (i) "Investor" means the Initial  Investor and any permitted  transferee
or


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assignee  who agrees to become  bound by the  provisions  of this  Agreement  in
accordance with Section 9 hereof.

        (ii)  "Potential  Material  Event" means any of the  following:  (a) the
possession by the Company of material  information  not ripe for disclosure in a
registration statement, which shall be evidenced by determinations in good faith
by the Board of Directors of the Company that disclosure of such  information in
the  registration  statement would be detrimental to the business and affairs of
the Company;  or (b) any material  engagement  or activity by the Company  which
would, in the good faith determination of the Board of Directors of the Company,
be adversely  affected by disclosure in a  registration  statement at such time,
which  determination  shall be accompanied by a good faith  determination by the
Board of  Directors  of the Company  that the  registration  statement  would be
materially misleading absent the inclusion of such information.

        (iii)   "Register,"   "Registered,"  and   "Registration"   refer  to  a
registration  effected  by  preparing  and filing a  Registration  Statement  or
Statements in compliance  with the Securities Act and pursuant to Rule 415 under
the Securities Act or any successor rule providing for offering  securities on a
continuous  basis ("Rule 415"), and the declaration or ordering of effectiveness
of such  Registration  Statement by the United  States  Securities  and Exchange
Commission (the "SEC").

        (iv) "Registrable Securities" means the Conversion Shares.

        (v)  "Registration  Statement"  means a  registration  statement  of the
Company under the Securities Act.

        (b) Capitalized terms used herein and not otherwise defined herein shall
have the respective meanings set forth in the Securities Purchase Agreement.

        2. Registration.

        (a) Mandatory Registration.  The Company shall prepare and file with the
SEC, as soon as possible  after the Closing  Date (as defined in the  Securities
Purchase  Agreement) but in no later than thirty (30) days following the Closing
Date, either a Registration  Statement on Form S-3 registering for resale by the
Investor a sufficient number of shares of Common Stock (or such lesser number as
may be required by the SEC,  but in no event less than the number of shares into
which the Preferred Stock would be convertible at the time of filing of the Form
S-3 (assuming for such purposes  that the  Additional  Preferred  Stock had been
issued at such date and all  Preferred  Stock was then eligible to be converted,
and had been converted,  into Conversion  Shares in accordance with the terms of
the Certificate of  Designations,  whether or not such issuance,  eligibility or
conversion  had in fact occurred as of such date) or an amendment to any pending
Company Registration  Statement on Form S-3, and such Registration  Statement or
amended Registration Statement shall state that, in accordance with Rule 416 and
457 under the  Securities  Act,  it also  covers  such  indeterminate  number of
additional  shares of Common Stock as may become issuable upon conversion of the
Preferred Stock resulting from adjustment in the


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Conversion  Price, or to prevent dilution  resulting from stock splits, or stock
dividends),  which  Registration  Statement shall be declared effective no later
than  ninety  (90) days  after the  Closing  Date.  If at any time the number of
shares of Common Stock into which the Preferred  Stock may be converted  exceeds
the  aggregate  number of shares of Common  Stock then  registered,  the Company
shall,  within ten (10) business days after receipt of a written notice from any
Investor,  either  (i) amend the  Registration  Statement  filed by the  Company
pursuant to the preceding sentence, if such Registration  Statement has not been
declared  effective  by the SEC at that time,  to register  all shares of Common
Stock  into  which  the  Preferred  Stock  may be  converted,  or  (ii)  if such
Registration Statement has been declared effective by the SEC at that time, file
with the SEC an  additional  Registration  Statement on Form S-3 to register the
shares of Common  Stock into which the  Preferred  Stock may be  converted  that
exceed the aggregate number of shares of Common Stock already registered.

        (b) Payments by the Company.

        (i) If the Registration Statement covering the Registrable Securities is
not filed in proper form with the SEC within  thirty (30) days after the Closing
Date (the "Required Filing Date"),  the Company will make payment to the Initial
Investor in such  amounts and at such times as shall be  determined  pursuant to
this Section 2(b).

        (ii) If the Registration  Statement covering the Registrable  Securities
is not effective (a) within the earlier of (1) fifteen (15) days after notice by
the SEC that it may be declared  effective or (2) ninety (90) days following the
Closing Date (the "Required  Effective  Date"), or (b) after a Suspension Period
(as defined below),  then the Company will make payments to the Initial Investor
in such  amounts  and at such  times  as shall be  determined  pursuant  to this
Section 2(b).

        (iii)  Subject to Section  2(b)(vi)  below,  the amount  (the  "Periodic
Amount") to be paid by the Company to the Initial  Investor  shall be determined
as of each Computation Date (as defined below) and such amount shall be equal to
(A) two percent (2%) of the  purchase  price paid by the Initial  Investor  (the
"Purchase  Price") for all  Preferred  Shares  then  purchased  and  outstanding
pursuant  to the  Securities  Purchase  Agreement  for the period  from the date
following the Required  Filing Date or the Required  Effective Date, as the case
may be, to the first  relevant  Computation  Date, and (B) three percent (3%) to
each Computation  Date thereafter.  By way of illustration and not in limitation
of the  foregoing,  if the  Registration  Statement  is timely  filed but is not
declared  effective  until one hundred  sixty-five  (165) days after the Closing
Date,  the Periodic  Amount will  aggregate  eight  percent (8%) of the purchase
price of the  Preferred  Shares (2% for days 91-120,  plus 3% for days  121-150,
plus 3% for days 151-165).

        (iv) Each  Periodic  Amount  will be payable  by the  Company in cash or
other immediately available funds to the Investor upon demand of the Investor.

        (v) The parties  acknowledge  that the damages  which may be incurred by
the Investor if the  Registration  Statement is not filed by the Required Filing
Date or if the  Registration  Statement has not been  declared  effective by the
Required Registration Date may be difficult to ascertain. The parties agree that
the Periodic Amount represent a reasonable  estimate on the part of the parties,
as of the  date  of  this  Agreement,  of  the  amount  of  such  damages.  (vi)
Notwithstanding  the foregoing,  the amounts payable by the Company  pursuant to
this provision shall not be payable to the extent any delay in the effectiveness
of the  Registration  Statement occurs because of an act of, or a failure to act
or to act timely by the Initial Investor or its counsel, or as a result of force
majeure, or in the event all of the Registrable  Securities may be sold pursuant
to Rule 144 or another available exemption under the Act.

        (vii)  "Computation Date" means (i) the date which is the earlier of (A)
thirty (30) days after the Required Filing Date and the Required Effective Date,
as the case may be,  or (B) the  date  after  the  Required  Filing  Date or the
Required  Registration  Date on which the Registration  Statement is filed (with
respect to payments due as  contemplated  by Section 2(b)(i) hereof) or declared
effective  (with  respect to payments due as  contemplated  by Section  2(b)(ii)
hereof) or after any Permitted  Suspension  Period, as the case may be, and (ii)
each date  which is the  earlier  of (A)  thirty  (30) days  after the  previous
Computation  Date or (B) the date after the previous  Computation  Date on which
the   Registration   Statement  is  filed  (with  respect  to  payments  due  as
contemplated by Section  2(b)(i) hereof) or declared  effective (with respect to
payments due as contemplated by Section 2(b)(ii) hereof), as the case may be.

        3.  Obligations of the Company.  In connection with the  registration of
the Registrable Securities, the Company shall do each of the following.

        (a)  Prepare  promptly,  and file with the SEC by thirty (30) days after
the Closing  Date, a  Registration  Statement  with respect to not less than the
number of Registrable  Securities provided in Section 2(a) above, and thereafter
use its reasonable best efforts to cause each Registration Statement relating to
Registrable  Securities to become effective the earlier of (a) fifteen (15) days
after  notice by the SEC that it may be declared  effective,  or (b) ninety (90)
days after the Closing Date, and keep the  Registration  Statement  effective at
all times until the earliest (the "Registration Period") of (i) the date that is
two years after the Closing Date,  (ii) the date when the Investors may sell all
Registrable  Securities under Rule 144 or (iii) the date the Investors no longer
own any of the Registrable  Securities,  which Registration Statement (including
any amendments or supplements thereto and prospectuses  contained therein) shall
not contain any untrue  statement of a material fact or omit to state a material
fact required to be stated therein or necessary to make the statements  therein,
in light of the circumstances in which they were made, not misleading;

        (b)   Prepare  and  file  with  the  SEC  such   amendments   (including
post-effective amendments) and supplements to the Registration Statement and the
prospectus  used  in  connection  with  the  Registration  Statement  as  may be
necessary  to  keep  the   Registration   effective  at  all  times  during  the
Registration  Period,  and,  during the  Registration  Period,  comply  with the
provisions  of  the  Securities  Act  with  respect  to the  disposition  of all
Registrable  Securities  of the Company  covered by the  Registration  Statement
until such time as all of such  Registrable  Securities have been disposed of in
accordance  with the intended  methods of  disposition  by the seller or sellers
thereof as set forth in the Registration Statement;

        (c) The Company shall permit a single firm of counsel  designated by the
Initial  Investors to review the  Registration  Statement and all amendments and
supplements  thereto a  reasonable  period of time (but not less than  three (3)
business  days) prior to their filing with the SEC, and not file any document in
a form to which such counsel reasonably objects.

        (d) Furnish to each Investor whose  Registrable  Securities are included
in the Registration  Statement and its legal counsel  identified to the Company,
(i) promptly after the same is prepared and publicly distributed, filed with the
SEC, or received by the  Company,  one (1) copy of the  Registration  Statement,
each  preliminary  prospectus and  prospectus,  and each amendment or supplement
thereto, and (ii) such number of copies of a prospectus,  and all amendments and
supplements  thereto and such other  documents,  as such Investor may reasonably
request in order to facilitate  the  disposition of the  Registrable  Securities
owned by such Investor;

        (e) As  promptly  as  practicable  after  becoming  aware of such event,
notify  each  Investor  of the  happening  of any event of which the Company has
knowledge,  as a result of which the  prospectus  included  in the  Registration
Statement, as then in effect, includes an untrue statement of a material fact or
omits to state a material  fact  required to be stated  therein or  necessary to
make the statements therein, in light of the circumstances under which they were
made, not misleading,  and use its best efforts promptly to prepare a supplement
or amendment to the Registration  Statement or other appropriate filing with the
SEC to correct such untrue statement or omission, and deliver a number of copies
of such supplement or amendment to each Investor as such Investor may reasonably
request;

        (f) As  promptly  as  practicable  after  becoming  aware of such event,
notify each  Investor who holds  Registrable  Securities  being sold (or, in the
event of an underwritten offering, the managing underwriters) of the issuance by
the SEC of a Notice of  Effectiveness or any notice of effectiveness or any stop
order or other suspension of the effectiveness of the Registration  Statement at
the earliest possible time;

        (g) Notwithstanding  the foregoing,  if at any time or from time to time
after the date of  effectiveness  of the  Registration  Statement,  the  Company
notifies  the  Investors  in writing of the  existence  of a Potential  Material
Event,  the Investors  shall not offer or sell any  Registrable  Securities,  or
engage  in any  other  transaction  involving  or  relating  to the  Registrable
Securities,  from the time of the giving of notice  with  respect to a Potential
Material Event until such Investor receives written notice from the Company that
such  Potential  Material  Event  either has been  disclosed to the public or no
longer  constitutes a Potential  Material  Event;  provided,  however,  that the
Company may not so suspend the right to such holders of  Registrable  Securities
for more than two twenty (20) day periods in the  aggregate  during any 12-month
period  ("Suspension  Period")  with at least a ten (10)  business  day interval
between such periods,  during the periods the Registration Statement is required
to be in effect;


        (h)  Use  its  reasonable  efforts  to  secure  designation  of all  the
Registrable  Securities  covered  by the  Registration  Statement  on the "Small
Capitalization  Market"  of  the  National  Association  of  Securities  Dealers
Automated Quotations System ("NASDAQ") within the meaning of Rule 11Aa2-1 of the
SEC under the Securities  Exchange Act of 1934, as amended (the "Exchange Act"),
and the quotation of the Registrable  Securities on The NASDAQ SmallCap  Market;
or if, despite the Company's reasonable efforts to satisfy the preceding clause,
the Company is  unsuccessful  in doing so, to secure  NASDAQ/OTC  Bulletin Board
authorization  and  quotation  for  such  Registrable  Securities  and,  without
limiting the  generality  of the  foregoing,  to arrange for at least two market
makers to register with the National  Association  of Securities  Dealers,  Inc.
("NASD") as such with respect to such Registrable Securities;

        (i)  Provide  a  transfer  agent  and  registrar,  which may be a single
entity, for the Registrable  Securities not later than the effective date of the
Registration Statement;

        (j) Cooperate with the Investors who hold  Registrable  Securities being
offered to facilitate the timely  preparation and delivery of  certificates  for
the Registrable  Securities to be offered pursuant to the Registration Statement
and  enable  such  certificates  for the  Registrable  Securities  to be in such
denominations  or amounts as the case may be, as the  Investors  may  reasonably
request,  and,  within three (3) business  days after a  Registration  Statement
which  includes  Registrable  Securities  is ordered  effective  by the SEC, the
Company shall deliver,  and shall cause legal counsel selected by the Company to
deliver,  to the transfer agent for the Registrable  Securities  (with copies to
the Investors  whose  Registrable  Securities are included in such  Registration
Statement) an appropriate instruction and opinion of such counsel; and

        (k)  Take  all  other  reasonable  actions  necessary  to  expedite  and
facilitate disposition by the Investor of the Registrable Securities pursuant to
the Registration Statement.

        4. Obligations of the Investors.  In connection with the registration of
the Registrable Securities, the Investors shall have the following obligations:

        (a) It shall be a condition  precedent to the obligations of the Company
to complete  the  registration  pursuant to this  Agreement  with respect to the
Registrable Securities of a particular Investor that such Investor shall furnish
to the Company such information  regarding  itself,  the Registrable  Securities
held by it, and the intended method of disposition of the Registrable Securities
held by it, as shall be reasonably  required to effect the  registration of such
Registrable  Securities and shall execute such documents in connection with such
registration as the Company may reasonably request. At least five (5) days prior
to the first anticipated filing date of the Registration Statement,  the Company
shall notify each  Investor of the  information  the Company  requires from each
such Investor (the "Requested  Information") if such Investor elects to have any
of  such  Investor's   Registrable   Securities  included  in  the  Registration
Statement.  If at least  two (2)  business  days  prior to the  filing  date the
Company  has  not  received  the  Requested  Information  from  an  Investor  (a
"Non-Responsive Investor"), then the Company may file the Registration Statement
without including Registrable Securities of such Non-Responsive Investor;

        (b) Each  Investor,  by such  Investor's  acceptance of the  Registrable
Securities,  agrees to cooperate with the Company as reasonably requested by the
Company  in  connection  with the  preparation  and  filing of the  Registration
Statement hereunder, unless such Investor has notified the Company in writing of
such  Investor's  election  to  exclude  all  of  such  Investor's   Registrable
Securities from the Registration Statement; and

        (c) Each  Investor  agrees  that,  upon  receipt of any notice  from the
Company of the  happening of any event of the kind  described in Section 3(e) or
3(f),  above,  such  Investor  will  immediately   discontinue   disposition  of
Registrable  Securities  pursuant to the  Registration  Statement  covering such
Registrable  Securities  until  such  Investor's  receipt  of the  copies of the
supplemented or amended prospectus  contemplated by Section 3(e) or 3(f) and, if
so directed by the Company,  such Investor  shall deliver to the Company (at the
expense of the Company) or destroy (and deliver to the Company a certificate  of
destruction)  all  copies  in  such  Investor's  possession,  of the  prospectus
covering  such  Registrable  Securities  current  at the time of receipt of such
notice.

        5.  Expenses  of  Registration.  All  reasonable  expenses,  other  than
underwriting   discounts   and   commissions   incurred   in   connection   with
registrations,  filings or qualifications  pursuant to Section 3, but including,
without limitation, all registration, listing, and qualifications fees, printers
and  accounting  fees,  the fees and  disbursements  of counsel for the Company,
shall be borne by the Company.

        6. Indemnification. In the event any Registrable Securities are included
in a Registration Statement under this Agreement:

        (a) To the extent permitted by law, the Company will indemnify and hold
harmless each Investor who holds such Registrable Securities,  the directors, if
any, of such Investor,  the officers, if any, of such Investor,  each person, if
any, who controls any Investor  within the meaning of the  Securities Act or the
Exchange Act (each, an "Indemnified Person" or "Indemnified Party"), against any
losses,  claims,  damages,  liabilities or expenses (joint or several)  incurred
(collectively,  "Claims")  to which  any of them may  become  subject  under the
Securities  Act,  the  Exchange  Act or  otherwise,  insofar as such  Claims (or
actions or proceedings,  whether  commenced or threatened,  in respect  thereof)
arise out of or are based upon any of the  following  statements,  omissions  or
violations  in  the  Registration  Statement,  or any  post-effective  amendment
thereof, or any prospectus included therein: (i) any untrue statement or alleged
untrue statement of a material fact contained in the  Registration  Statement or
any  post-effective  amendment  thereof or the  omission or alleged  omission to
state therein a material fact required to be stated therein or necessary to make
the  statements  therein not  misleading,  (ii) any untrue  statement or alleged
untrue  statement  of a material  fact  contained  in the final  prospectus  (as
amended  or  supplemented,  if  the  Company  files  any  amendment  thereof  or
supplement  thereto with the SEC) or the  omission or alleged  omission to state
therein any material fact  necessary to make the  statements  made  therein,  in
light of the  circumstances  under which the  statements  therein were made, not
misleading  or (iii) any  violation  or alleged  violation by the Company of the
Securities  Act,  the  Exchange  Act,  any state  securities  law or any rule or
regulation  under the Securities  Act, the Exchange Act or any state  securities
law (the matters in the foregoing clauses (i) through (iii) being, collectively,
"Violations").  Subject  to clause  (b) of this  Section  6, the  Company  shall
reimburse the Investors,  promptly as such expenses are incurred and are due and
payable,  for any legal fees or other  reasonable  expenses  incurred by them in
connection  with  investigating  or  defending  any such Claim.  Notwithstanding
anything  to  the  contrary  contained  herein,  the  indemnification  agreement
contained in this Section 6(a) shall not (I) apply to a Claim arising out
of or based upon a Violation  which  occurs in reliance  upon and in  conformity
with  information  furnished  in writing  to the  Company by or on behalf of any
Indemnified  Person  expressly for use in connection with the preparation of the
Registration  Statement or any such amendment thereof or supplement  thereto, if
such  prospectus  was timely made  available by the Company  pursuant to Section
3(c) hereof; (II) be available to the extent such Claim is based on a failure of
the Investor to deliver or cause to be delivered the  prospectus  made available
by the  Company;  or (III) apply to amounts paid in  settlement  of any Claim if
such  settlement is effected  without the prior written  consent of the Company,
which consent shall not be unreasonably  withheld.  Each Investor will indemnify
the Company and its officers,  directors and agents  against any claims  arising
out of or based upon a Violation which occurs in reliance upon and in conformity
with  information  furnished in writing to the Company,  by or on behalf of such
Investor,   expressly  for  use  in  connection  with  the  preparation  of  the
Registration  Statement,  subject  to such  limitations  and  conditions  as are
applicable  to the  Indemnification  provided by the Company to this  Section 6.
Such  indemnity  shall  remain  in  full  force  and  effect  regardless  of any
investigation  made by or on behalf of the Indemnified  Person and shall survive
the transfer of the Registrable  Securities by the Investors pursuant to Section
9.

        (b) Promptly after receipt by an Indemnified Person or Indemnified Party
under this Section 6 of notice of the commencement of any action  (including any
governmental  action),  such Indemnified Person or Indemnified Party shall, if a
Claim in respect thereof is to be made against any indemnifying party under this
Section  6,  deliver  to  the  indemnifying   party  a  written  notice  of  the
commencement  thereof  and the  indemnifying  party  shall  have  the  right  to
participate in, and, to the extent the  indemnifying  party so desires,  jointly
with any other indemnifying  party similarly  noticed,  to assume control of the
defense thereof with counsel mutually satisfactory to the indemnifying party and
the Indemnified Person or the Indemnified Party, as the case may be. In case any
such action is brought against any Indemnified  Person or Indemnified Party, and
it notifies the indemnifying party of the commencement thereof, the indemnifying
party will be entitled to  participate  in, and, to the extent that it may wish,
jointly with any other indemnifying party similarly notified, assume the defense
thereof,  subject to the  provisions  herein  stated and after  notice  from the
indemnifying  party  to such  Indemnified  Person  or  Indemnified  Party of its
election so to assume the defense thereof,  the  indemnifying  party will not be
liable to such Indemnified  Person or Indemnified Party under this Section 6 for
any legal or other reasonable  out-of-pocket  expenses  subsequently incurred by
such  Indemnified  Person or  Indemnified  Party in connection  with the defense
thereof other than reasonable  costs of  investigation,  unless the indemnifying
party  shall not  pursue  the action of its final  conclusion.  The  Indemnified
Person or Indemnified  Party shall have the right to employ separate  counsel in
any such  action and to  participate  in the defense  thereof,  but the fees and
reasonable out-of-pocket expenses of such counsel shall not be at the expense of
the indemnifying  party if the indemnifying party has assumed the defense of the
action  with  counsel  reasonably  satisfactory  to the  Indemnified  Person  or
Indemnified  Party.  The failure to deliver  written notice to the  indemnifying
party within a reasonable time of the  commencement of any such action shall not
relieve such  indemnifying  party of any liability to the Indemnified  Person or
Indemnified  Party  under  this  Section  6,  except  to  the  extent  that  the
indemnifying  party is  prejudiced  in its  ability to defend such  action.  The
indemnification required by this Section 6 shall be made by periodic payments of
the amount thereof during the course of the  investigation  or defense,  as such
expense,  loss,  damage  or  liability  is  incurred  and  is due  and  payable.
Contribution.  To the extent any  indemnification  by an  indemnifying  party is
prohibited or limited by law, the indemnifying  party agrees to make the maximum
contribution  with respect to any amounts for which it would otherwise be liable
under Section 6 to the fullest extent permitted by law; provided,  however, that
(a) no contribution shall be made under  circumstances where the maker would not
have been  liable for  indemnification  under the fault  standards  set forth in
Section  6;  (b) no  seller  of  Registrable  Securities  guilty  of  fraudulent
misrepresentation  (within the meaning of Section 11(f) of the  Securities  Act)
shall be entitled to contribution from any seller of Registrable  Securities who
was not guilty of such fraudulent misrepresentation; and (c) contribution by any
seller of Registrable Securities shall be limited in amount to the net amount of
proceeds received by such seller from the sale of such Registrable Securities.

        8. Reports under  Exchange  Act. With a view to making  available to the
Investors the benefits of Rule 144  promulgated  under the Securities Act or any
other  similar  rule or  regulation  of the SEC that may at any time  permit the
Investors to sell  securities of the Company to the public without  registration
("Rule 144"), the Company agrees to:

        (a) make and keep  public  information  available,  as those  terms  are
understood and defined in Rule 144;

        (b) file with the SEC in a timely manner all reports and other documents
required of the Company under the Securities Act and the Exchange Act; and

        (c) furnish to each Investor so long as such  Investor owns  Registrable
Securities,  promptly upon request,  (i) a written statement by the Company that
it has complied with the reporting  requirements of Rule 144, the Securities Act
and the Exchange Act, (ii) a copy of the most recent annual or quarterly  report
of the Company and such other  reports and documents so filed by the Company and
(iii)  such  other  information  as may be  reasonably  requested  to permit the
Investors to sell such securities pursuant to Rule 144 without registration.

        9. Assignment of the Registration Rights. The rights to have the Company
register   Registrable   Securities   pursuant  to  this   Agreement   shall  be
automatically  assigned by the Investors to any  transferee  of the  Registrable
Securities  (or all or any  portion of any  Debenture  of the  Company  which is
convertible  into such  securities)  only if: (a) the Investor agrees in writing
with the  transferee  or  assignee  to assign  such  rights,  and a copy of such
agreement  is  furnished  to the  Company  within a  reasonable  time after such
assignment,  (b) the Company is, within a reasonable time after such transfer or
assignment,  furnished  with written  notice of (i) the name and address of such
transferee  or  assignee  and (ii) the  securities  with  respect  to which such
registration rights are being transferred or assigned, (c) immediately following
such transfer or assignment the further  disposition  of such  securities by the
transferee or assignee is restricted  under the  Securities  Act and  applicable
state  securities  laws, and (d) at or before the time the Company  received the
written  notice  contemplated  by clause (b) of this sentence the  transferee or
assignee agrees in writing with the Company to be bound by all of the provisions
contained  herein.  In the event of any delay in filing or  effectiveness of the
Registration Statement as a result of such assignment,  the Company shall not be
liable for any damages  arising  from such delay,  or the  payments set forth in
Section 2(c) hereof.

        10.Amendment of Registration Rights. Any provision of this Agreement may
be amended and the observance  thereof may be waived  (either  generally or in a
particular  instance and either  retroactively or prospectively),  only with the
written  consent of the Company and  Investors  who hold an eighty (80%) percent
interest of the  Registrable  Securities.  Any  amendment or waiver  effected in
accordance  with this  Section 10 shall be binding  upon each  Investor  and the
Company.

        11. Miscellaneous.

        (a) A  person  or  entity  is  deemed  to  be a  holder  of  Registrable
Securities  whenever  such  person or entity  owns of  record  such  Registrable
Securities.  If  the  Company  receives  conflicting  instructions,  notices  or
elections  from  two or more  persons  or  entities  with  respect  to the  same
Registrable  Securities,  the Company shall act upon the basis of  instructions,
notice  or  election  received  from the  registered  owner of such  Registrable
Securities.

        (b) Notices  required or  permitted  to be given  hereunder  shall be in
writing and shall be deemed to be sufficiently  given when personally  delivered
(by  hand,  by  courier,  by  telephone  line  facsimile  transmission,  receipt
confirmed,  or other means) or sent by certified mail, return receipt requested,
properly  addressed  and with proper  postage  pre-paid  (i) if to the  Company,
XYBERNAUT  CORPORATION,  12701 Fair Lakes Circle,  Suite 550, Fairfax,  Virginia
22033, ATTN: Steven Newman Telecopier No.: (703) 631-7070; with a copy to Parker
Chapin  Flattau & Klimpl,  LLP, 1211 Avenue of the Americas,  New York, New York
10036, ATTN: Martin Eric Weisberg, Esq., Telecopier No.: (212) 704-6288; (ii) if
to the  Initial  Investor,  at the  address  set  forth  under  its  name in the
Securities  Purchase Agreement,  with a copy to Samuel Krieger,  Esq., Krieger &
Prager, 319 Fifth Avenue, Third Floor, New York, NY 10016, Telecopier No.: (212)
213-2077;  and (iii) if to any other Investor,  at such address as such Investor
shall have provided in writing to the Company,  or at such other address as each
such party furnishes by notice given in accordance with this Section 11(b),  and
shall be effective, when personally delivered, upon receipt and, when so sent by
registered  or certified  mail,  four (4) calendar  days after  deposit with the
United States Postal Service.

        (c)  Failure  of any party to  exercise  any right or remedy  under this
Agreement or otherwise,  or delay by a party in exercising such right or remedy,
shall not operate as a waiver thereof.

        (a) This  Agreement  shall be governed by and  interpreted in accordance
with the laws of the State of New York without  giving effect to the  principles
thereof  regarding  the  conflict of laws.  Each of the parties  consents to the
jurisdiction  of the federal  courts whose  districts  encompass any part of the
City of New York or the state  courts of the  State of New York  sitting  in the
City of New York in connection with any dispute arising under this Agreement and
hereby waives, to the maximum extent permitted by law, any objection,  including
any  objection  based  on  forum  non  coveniens,  to the  bringing  of any such
proceeding in such jurisdictions.

        (b) If any provision of this Agreement shall be invalid or unenforceable
in any jurisdiction,  such invalidity or  unenforceability  shall not affect the
validity or enforceability of the remainder of this Agreement or the validity or
enforceability of this Agreement in any other jurisdiction.

        (c)  Subject to the  requirements  of Section 9 hereof,  this  Agreement
shall inure to the benefit of and be binding upon the  successors and assigns of
each of the parties hereto.

        (d) All  pronouns and any  variations  thereof  refer to the  masculine,
feminine or neuter, singular or plural, as the context may require.

        (e) The headings in this Agreement are for convenience of reference only
and shall not limit or otherwise affect the meaning thereof.

        (i) This Agreement may be executed in one or more counterparts,  each of
which shall be deemed an original but all of which shall  constitute one and the
same agreement.  This Agreement,  once executed by a party,  may be delivered to
the other party hereto by telephone  line  facsimile  transmission  of a copy of
this Agreement bearing the signature of the party so delivering this Agreement.

        (j) The Company  acknowledges that any failure by the Company to perform
its  obligations  under  Section 3(a) hereof,  or any delay in such  performance
could result in loss to the Investors,  and the Company agrees that, in addition
to any other  liability the Company may have by reason of such failure or delay,
the Company shall be liable for all direct  damages,  if any, caused by any such
failure or delay,  unless the same is the result of force majeure, or actions on
the part of the  Investor.  Neither  party  shall be  liable  for  consequential
damages.

        (k) This Agreement  constitutes  the entire  agreement among the parties
hereto with respect to the subject  matter  hereof.  There are no  restrictions,
promises, warranties or undertakings,  other than those set forth or referred to
herein. This Agreement  supersedes all prior agreements and understandings among
the parties hereto with respect to the subject matter hereof. This Agreement may
be amended only by an  instrument  in writing  signed by the party to be charged
with enforcement thereof.

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                                        3





        IN WITNESS  WHEREOF,  the parties have caused this  Agreement to be duly
executed by their  respective  officers  thereunto duly authorized as of the day
and year first above written.

                                                    XYBERNAUT CORPORATION


                                                    By:
                                                        -----------------------
                                                    Name:
                                                    Title:


                                                    ---------------------------

                                                    By:
                                                        -----------------------
                                                    Name:
                                                    Title:


                                        4







                                                                        ANNEX V


                               COMPANY DISCLOSURE
                               ------------------


Section 3(j):                             None

Section 3(k):                             None

Section 3(l):                             On June  30,  1997,  the  Company
                                          issued   3,000   shares  of  Series  A
                                          Preferred  Stock.  As of September 30,
                                          1997, twenty-five (25%) percent of the
                                          Series A  Preferred  Stock  have  been
                                          converted  into  Common  Stock  of the
                                          Company.


                                        5