THE SECURITIES  REPRESENTED  HEREBY (THE  "SECURITIES") HAVE NOT BEEN REGISTERED
UNDER THE  SECURITIES  ACT OF 1933, AS AMENDED (THE  "SECURITIES  ACT"),  OR THE
SECURITIES  LAWS OF ANY  STATE  AND MAY NOT BE SOLD OR  OFFERED  FOR SALE IN THE
ABSENCE OF AN EFFECTIVE  REGISTRATION STATEMENT FOR THE SECURITIES OR AN OPINION
OF  COUNSEL  OR  OTHER  EVIDENCE   ACCEPTABLE  TO  THE  CORPORATION   THAT  SUCH
REGISTRATION IS NOT REQUIRED.


                          COMMON STOCK PURCHASE WARRANT


                              XYBERNAUT CORPORATION


                              Expires July 29, 2006


No.:  W-1009                                        Number of Shares: 39,735
Date of Issuance:  July 30, 2001

          1. Issuance. For good and valuable consideration, the receipt of which
is hereby  acknowledged by Xybernaut  Corporation,  a Delaware  corporation (the
"Company"),  DA  VINCI  INTERNATIONAL  LTD.,  or  its  registered  assigns  (the
"Holder")  is hereby  granted the right to purchase at any time until 5:00 P.M.,
New York City  time,  on July 29,  2006 (the  "Expiration  Date"),  Thirty  Nine
Thousand Seven Hundred and Thirty Five (39,735)  shares of the Company's  Common
Stock,  par value $.01 per share  (the  "Common  Stock") at an initial  exercise
price of $4.53 per share (the "Exercise  Price"),  subject to further adjustment
as set forth in Section 6 hereof.

          2. Exercise of Warrants.  This Warrant is  exercisable  in whole or in
part at the Exercise Price per share of Common Stock payable hereunder,  payable
in cash or by certified or official bank check.  Upon  surrender of this Warrant
Certificate  with the annexed  Notice of Exercise Form duly  executed,  together
with payment of the Exercise Price for the shares of Common Stock purchased, the
Holder shall be entitled to receive a certificate or certificates for the shares
of Common Stock so purchased.

          3. Reservation of Shares.  The Company hereby agrees that at all times
during the term of this  Warrant  there  shall be  reserved  for  issuance  upon
exercise of this  Warrant  such number of shares of its Common Stock as shall be
required for issuance upon exercise of this Warrant (the "Warrant Shares").

          4.  Mutilation  or Loss of  Warrant.  Upon  receipt by the  Company of
evidence  satisfactory  to it of the loss,  theft,  destruction or mutilation of
this  Warrant,  and (in the  case of  loss,  theft or  destruction)  receipt  of
reasonably  satisfactory  indemnification,  and (in the case of mutilation) upon
surrender and cancellation of this Warrant, the Company will execute and





deliver  a new  Warrant  of like  tenor  and  date and any  such  lost,  stolen,
destroyed or mutilated Warrant shall thereupon become void.

          5. Rights of the Holder.  The Holder shall not, by virtue  hereof,  be
entitled to any rights of a stockholder in the Company, either at law or equity,
and the rights of the Holder are limited to those  expressed in this Warrant and
are not enforceable against the Company except to the extent set forth herein.

          6. Protection Against Dilution.

             (a) Adjustment Mechanism. If an adjustment of the Exercise Price is
required  pursuant to this  Section 6, the Holder  shall be entitled to purchase
such  number of  additional  shares of Common  Stock as will cause (i) the total
number of shares of Common Stock Holder is entitled to purchase pursuant to this
Warrant,  multiplied  by (ii) the adjusted  purchase  price per share,  to equal
(iii) the dollar  amount of the total number of shares of Common Stock Holder is
entitled to purchase  before  adjustment  multiplied by the total purchase price
before adjustment.

             (b)  Capital  Adjustments.  In case of any stock  split or  reverse
stock   split,   stock   dividend,   reclassification   of  the  Common   Stock,
recapitalization,  merger or consolidation, or like capital adjustment affecting
the Common  Stock of the  Company,  the  provisions  of this  Section 6 shall be
applied as if such capital  adjustment event had occurred  immediately  prior to
the date of this  Warrant  and the  original  purchase  price  had  been  fairly
allocated  to the stock  resulting  from such capital  adjustment;  and in other
respects the provisions of this Section 6 shall be applied in a fair,  equitable
and reasonable manner so as to give effect, as nearly as may be, to the purposes
hereof. A rights offering to stockholders of the Company shall be deemed a stock
dividend to the extent of the bargain purchase element of the rights.

          7.  Warrant  Call.  At any  time  or  from  time  to  time  after  the
Registration  Statement  (as defined in Section 8(b)  hereof) has been  declared
effective,  the Company,  at its option,  may, upon written notice to the Holder
(the "Call  Notice"),  call up to one hundred  percent (100%) of this Warrant if
the Common  Stock trades at a price equal to or greater than $6.50 per share for
five (5)  consecutive  trading  days  prior to the date the  Company  calls  the
Warrant.  To be  effective,  the Call Notice must be given  within ten (10) days
after the aforementioned  five (5) day period. The rights and privileges granted
pursuant to this Warrant with respect to such Warrant Shares subject to the Call
Notice shall  terminate if this  Warrant is not  exercised  with respect to such
Warrant  Shares by the  Holder  within  ten (10) days  after the Call  Notice is
received by the Holder.  In the event that this Warrant is not  exercised by the
Holder  with  respect to the Warrant  Shares  subject to the Call  Notice,  this
Warrant shall expire at 5:00 p.m.  eastern time on the call date and the Company
will remit to the Holder $0.01 per Warrant  Share and a new Warrant  certificate
representing  the number of Warrant  Shares,  if any, with respect to which this
Warrant  has not been  exercised  or subject to a Call  Notice  upon such Holder
tendering to the Company the expired Warrant certificate.



                                       2


        8.   Transfer  to  Comply  with  the  Securities  Act;
             Registration Rights.

             (a) This Warrant has not been  registered  under the Securities Act
of 1933, as amended (the "Act"),  or any applicable  state  securities laws, and
has  been  issued  to the  Holder  for  investment  and  not  with a view to the
distribution of either the Warrant or the Warrant  Shares.  Neither this Warrant
nor any of the Warrant  Shares or any other  security  issued or  issuable  upon
exercise of this Warrant may be sold,  transferred,  pledged or  hypothecated in
the absence of an  effective  registration  statement  under the Act relating to
such  security  or an  opinion  of  counsel  satisfactory  to the  Company  that
registration  is not required under the Act. Each  certificate  for the Warrant,
the Warrant  Shares and any other  security  issued or issuable upon exercise of
this Warrant shall  contain a legend on the face thereof,  in form and substance
satisfactory  to counsel for the  Company,  setting  forth the  restrictions  on
transfer contained in this Section.

             (b) The Company agrees to file a registration statement, which
shall include the Warrant Shares, on Form S-3 or another available form (the
"Registration Statement"), pursuant to the Registration Rights Agreement between
the Company and the Holder dated as of July 30, 2001 (the "Registration Rights
Agreement").

          9. Notices.  Any notice or other  communication  required or permitted
hereunder  shall be in writing and shall be delivered  personally,  telegraphed,
telexed,  sent by facsimile  transmission  or sent by  certified,  registered or
express mail,  postage  pre-paid.  Any such notice shall be deemed given when so
delivered personally,  telegraphed,  telexed or sent by facsimile  transmission,
or, if mailed,  two (2) days  after the date of  deposit  in the  United  States
mails, as follows:

             if to the Company, to:

                     Xybernaut Corporation
                     12701 Fair Lakes Circle
                     Suite  550
                     Fairfax, Virginia 22033
                     Attn:  John F. Moynahan, Sr. Vice President
                     and Chief Financial Officer
                     Telephone No.: (703) 631-6925
                     Facsimile No.: (703) 631-3903

             with a copy to:

                     Jenkens & Gilchrist Parker Chapin LLP
                     The Chrysler Building
                     405 Lexington Avenue
                     New York, New York  10174
                     Attn: Martin Eric Weisberg, Esq.
                     Telephone No.: (212) 704-6000
                     Facsimile No.: (212) 704-6288



                                       3


The  address  with  respect to the Holder of this  Warrant or of Warrant  Shares
issued  pursuant  hereto  shall be its last known  address or  facsimile  number
appearing on the books of the Company  maintained for such  purposes.  Any party
may be notice  given in  accordance  with  this  Section  to the  other  parties
designate another address or person for receipt of notices hereunder.

          10. Supplements and Amendments;  Whole Agreement.  This Warrant may be
amended or  supplemented  only by an instrument in writing signed by the parties
hereto. This Warrant and the Purchase Agreement,  of even date herewith,  by and
between the Company and the Holder contain the full understanding of the parties
hereto with  respect to the subject  matter  hereof and thereof and there are no
representations,  warranties,  agreements or understandings other than expressly
contained herein and therein.

          11.  Governing Law. This Warrant shall be deemed to be a contract made
under the laws of the State of New York and for all  purposes  shall be governed
by and  construed  in  accordance  with the  laws of such  State  applicable  to
contracts to be made and performed entirely within such State.

          12.  Counterparts.  This  Warrant  may be  executed  in any  number of
counterparts and each of such  counterparts  shall for all purposes be deemed to
be an original,  and all such counterparts shall together constitute but one and
the same instrument.

          13. Descriptive Headings. Descriptive headings of the several Sections
of this  Warrant  are  inserted  for  convenience  only and shall not control or
affect the meaning or construction of any of the provisions hereof.

                  [Remainder of Page Intentionally Left Blank]


                                       4




      IN WITNESS WHEREOF, the parties hereto have executed this Warrant as of
the 30th day of July 2001.


                                XYBERNAUT CORPORATION



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


                                       5





                          NOTICE OF EXERCISE OF WARRANT

     The  undersigned   hereby   irrevocably   elects  to  exercise  the  right,
represented by the Warrant  Certificate  No. W-___ dated as of July 30, 2001, to
purchase  __________  shares of the Common Stock,  par value $.01 per share,  of
Xybernaut  Corporation and tenders herewith payment in accordance with Section 1
of said Common Stock Purchase Warrant.

     Please deliver the stock certificate to:





Dated:
      --------------------




                                        By:
                                           ----------------------------------




                                       6