Investor Contact Cindy Klimstra Director, Investor Relations 847-968-0268 cklimstra@cdw.com   CDW Corporation to Present at Bank of America Investment Conference VERNON HILLS, Ill. - September 15, 2005 – CDW Corporation (NASDAQ: CDWC), a leading provider of technology products and services to business, government and education, today announced that the company is scheduled to present on Thursday, September 22, 2005, at the Bank of America 35th Annual Investment Conference, The Ritz-Carlton Hotel, San Francisco. Representing the company will be James R. Shanks, executive vice president and president, CDW Government, Inc. A live audio webcast of the presentation and breakout session will be accessible at www.cdw.com/investor at 11:30 a.m. ET / 8:30 a.m. PT. A replay will be available for approximately two weeks. About CDW CDW® (NASDAQ: CDWC), ranked No. 347 on the FORTUNE 500, is a leading provider of technology products and services for business, government and education. CDW is a principal source of technology from top name brands such as Adobe, APC, Apple, Cisco, HP, IBM, Microsoft, Sony, Symantec, Toshiba and ViewSonic. CDW was founded in 1984 and today employs approximately 4,000 coworkers. In 2004, the company generated sales of $5.7 billion. CDW's direct model offers one-on-one relationships with knowledgeable account managers; purchasing by telephone, fax, the company's award-winning CDW.com web site, customized CDW@work™ extranets, CDWG.com web site and macwarehouse.com web site; custom configured solutions and same day shipping; and pre- and post-sales technical support, with approximately 120 factory-trained and A+ certified technicians on staff. For more information about CDW: Visit CDW on the Internet at http://www.cdw.com. Contact CDW Investor Relations via the Internet at investorrelations@cdw.com or by telephone at 847-419-6328.