Investor Inquiries Cindy Klimstra Vice President, Investor Relations (847) 968-0268 Media Inquiries Gary Ross Sr. Manager, Corporate Communications (847) 371-5048 CDW Promotes Cindy Thorson Klimstra to Vice President Investor Relations Vernon Hills, Ill. - December 22, 2005 - CDW Corporation (NASDAQ: CDWC) a leading provider of technology products and services to business, government and education, today announced Cindy Thorson Klimstra, 43, has been promoted to vice president investor relations, effective January 1, 2006. Klimstra joined CDW as director of investor relations in October 2003 and is responsible for all investor relations activities for the company. Klimstra's investor relations career spans 13 years. Prior to CDW, she served as assistant vice president of investor relations at Cobalt Corporation, senior vice president of business development at investor relations consulting firm Ashton Partners, and vice president of investor relations at First Industrial Realty Trust, Inc. Klimstra reports to Barbara Klein, senior vice president and chief financial officer. Klimstra holds a bachelor's degree from the University of Wyoming and an MBA from Northwestern University. About CDW CDW®, ranked No. 347 on the FORTUNE 500, is a leading provider of technology solutions for business, government and education. CDW is a principal source of technology products and services including 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 4,100 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.