CDW Ranked Among 10 Largest Online Retailers.

CDW.com Listed as No. 8 on Internet Retailer's Top 500 Retail Web Sites Guide

VERNON HILLS, Ill. -- CDW Corporation (NASDAQ: CDWC), a leading provider of technology products and services to business, government and education, was recently ranked No.8 on the list of America's 500 largest e-retailers. CDW appears alongside other well-known companies like Amazon.com, Sears and OfficeMax in Internet Retailer's Top 500 Retail Web Sites Guide.

CDW is No. 8 on the list with approximately 1.9 billion in annual online sales in 2006, which accounted for 29.7 percent of the company's total annual sales of information technology products and services. This is the third consecutive year that CDW has been ranked No. 8.

"Our online capabilities play a crucial role in enabling us to provide our customers with the technology they need, when they need it," said Jonathan J. Stevens, chief information officer, CDW. "We are pleased to be ranked as a Top 10 e-retailer and remain committed to creating an engaging experience for our Web buyers."

CDW's Web site provides customers with a variety of features and customized extranet sites, called CDW@work, that allow them to order products and services online, as well as view their account information including purchases, order status, cost estimate quotes and purchase history. CDW also offers customers additional online features like the Software License Tracker, which helps them manage complex software licensing agreements and in turn better manage their IT systems.

Internet Retailer's definitive ranking and analysis of America's 500 largest e-retailers is based on annual 2006 Internet sales, researched by Internet Retailer and confirmed by retailers. This report includes company financial, operational and performance data, as well as vendors in 16 key categories.

About Internet Retailer

Published by Chicago-based Vertical Web Media LLC, Internet Retailer is a monthly national business magazine, web site, conference and directory that serve the retailing community. The Internet Retailer family of products focuses on the Internet's vital role in a wide array of retailing activities, including web merchandising, supply chain management and multi-channel integration. Its 40,000+ subscribers are senior executives primarily from retail chains, independent stores, catalogs, virtual merchants and brand-name manufacturers. Internet Retailer's circulation represents the largest multi-channel readership base of any retailing magazine. The magazine also publishes the most widely read e-mail newsletter in retailing, IRNewsLink, which is distributed twice-weekly to 35,000 opt-in subscribers, operates the largest retailing information web site, InternetRetailer.com, sponsors the largest conference in the e-retailing industry and publishes an annual ranking of the 500 largest web sites.

About CDW

CDW[R], ranked No. 342 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 Acer, Adobe, Apple, APC, Cisco, Fujitsu, HP, IBM, Lenovo, Microsoft, Panasonic, Quantum, Samsung, Sony, Symantec and ViewSonic. CDW's direct model offers customers one-on-one relationships with knowledgeable account managers and access to more than 820 on-staff engineers and advanced technology specialists who customize solutions for customers' complex technology needs. CDW also provides same-day product shipping and post-sales technical support.

CDW was founded in 1984 and employs approximately 5,640 coworkers. In 2006, the company generated sales of $6.8 billion. For more information, visit CDW.com.

CDW Corporation will file with the Securities and Exchange Commission (the "SEC"), and furnish to its shareholders, a proxy statement soliciting proxies for the meeting of its shareholders to be called with respect to the proposed merger between CDW and MDP. CDW SHAREHOLDERS ARE ADVISED TO READ THE PROXY STATEMENT WHEN IT IS FINALIZED AND DISTRIBUTED TO THEM BECAUSE IT WILL CONTAIN IMPORTANT INFORMATION. CDW shareholders and other interested parties will be able to obtain, without charge, a copy of the proxy statement (when available) and other relevant documents filed with the SEC from the SEC's website at http://www.sec.gov. CDW shareholders and other interested parties will also be able to obtain, without charge, a copy of the proxy statement (when available) and other relevant documents by directing a request by mail or telephone to CDW Corporation, 200 N. Milwaukee Ave., Vernon Hills, Illinois 60061, Attention: Corporate Secretary, telephone: [phone], or from CDW's website, http://www.cdw.com.

CDW and certain of its directors, executive officers and other members of management and employees may, under SEC rules, be deemed to be "participants" in the solicitation of proxies from shareholders of CDW with respect to the proposed merger. Information regarding the persons who may be considered "participants" in the solicitation of proxies will be set forth in CDW's proxy statement relating to the proposed merger when it is filed with the SEC. Information regarding certain of these persons and their beneficial ownership of CDW common stock as of March 31, 2007 is also set forth in CDW's proxy statement for its 2007 Annual Meeting of Shareholders, which was filed with the SEC on April 16, 2007.

Statements about the expected timing, completion and effects of the proposed merger between CDW and MDP, and all other statements in this press release other than historical facts, constitute forward-looking statements within the meaning of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Readers are cautioned not to place undue reliance on these forward-looking statements, each of which is qualified in its entirety by reference to the following cautionary statements. Forward-looking statements speak only as of the date hereof and are based on current expectations and involve a number of assumptions, risks and uncertainties that could cause actual results to differ materially from those projected in the forward-looking statements. CDW may not be able to complete the proposed merger because of a number of factors, including, among other things, the failure to obtain shareholder approval, the failure of financing or the failure to satisfy other closing conditions. Other risks and uncertainties that may affect forward-looking statements are described in the reports filed by CDW with the SEC under the Securities Exchange Act of 1934, as amended, including without limitation CDW's Annual Report on Form 10-K for the year ended December 31, 2006.