Insight Enterprises (NSIT) 10-Q 2003 Q1 Quarterly report

INSIGHT ENTERPRISES, INC.

Exhibit 99.1

CERTIFICATION PURSUANT TO
18 U.S.C. SECTION 1350,
AS ADOPTED PURSUANT TO
SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

     In connection with the Quarterly Report of Insight Enterprises, Inc. (the “Company”) on Form 10-Q for the period ended March 31, 2003 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Timothy A. Crown, Chief Executive Officer of Insight Enterprises, Inc., certify, pursuant to 18 U.S.C. §1350, as adopted pursuant to §906 of the Sarbanes-Oxley Act of 2002, that to the best of my knowledge:

     (1)  The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

     (2)  The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of Insight Enterprises, Inc..

By:	/s/ Timothy A. Crown
	Timothy A. Crown
	Chief Executive Officer
	May 13, 2003

This certification accompanies this Report pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 and shall not be deemed filed by the Company for purposes of Section 18 of the Securities Exchange Act of 1934, as amended. A signed original of this written statement required by Section 906 has been provided to the Company and will be retained by the Company and furnished to the Securities and Exchange Commission or its staff upon request.