Media Inquiries Gary Ross Sr. Manager, Corporate Communications 847-371-5048 garyross@cdw.com Investor Contact Cindy Klimstra Director, Investor Relations 847-968-0268 cklimstra@cdw.com CDW's Sales Increase 9.9 Percent in November 2005 VERNON HILLS, Ill. - December 9, 2005 - CDW Corporation (NASDAQ: CDWC), a leading provider of technology products and services to business, government and education, today announced November 2005 sales were $508.5 million, an increase of 9.9 percent compared to November 2004 sales of $462.7 million. Average daily sales for November 2005 were $24.214 million, an increase of 9.9 percent compared to average daily sales of $22.033 million for November 2004. There were 21 billing days in both November 2005 and November 2004. The corporate and public sector segments both grew at similar rates in November 2005. Product categories that achieved the strongest year-over-year unit volume growth for the month on an average daily basis included notebook CPUs, software, data storage, printers, video, and memory. The Company plans to announce December 2005 sales and fourth quarter earnings on Tuesday, January 24, 2006. December 2004 had 22 billing days and December 2005 will have 21 billing days. Forward Looking Statement Any forward-looking statements contained in this release are based on the Company's beliefs and expectations as of the date of this release and are subject to certain risks and uncertainties which may have a significant impact on the Company's business, operating results or financial condition. Should any risk or uncertainty materialize, or should underlying assumptions prove incorrect, actual results or outcomes may vary materially from those described in forward-looking statements. Factors affecting the Company's business and prospects are discussed in the Company's filings with the Securities and Exchange Commission. 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, Lenovo, 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. 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.