Please direct your media and public relations inquiries to: mediarelations@cdw.com 800-800-4CDW Constellation Energy Group Chooses CDW As Primary Supplier For I.T. Products VERNON HILLS, Ill. - February 23, 2004 - CDW (Nasdaq: CDWC), a leading provider of technology products and services for business, government and education, announced a partnership agreement whereby Constellation Energy Group (NYSE: CEG) has consolidated its information technology buying with CDW. A Baltimore-based Fortune 500 holding company, Constellation Energy Group is a $9.7 billion firm and the nation's leading competitive supplier of electricity to large commercial and industrial customers. It owns a number of energy-related businesses to market energy in North America and manages the associated risks. As well, it owns and operates a diversified fleet of generation plants throughout the United States. It also delivers electricity and natural gas through its regulated utility, the Baltimore Gas and Electric Company. "We chose CDW as our one-stop shop because of its superior technical sales assistance, Web site functionality and shipping abilities," said Beth Perlman, chief information officer, Constellation Energy. "Before we used CDW, it was difficult managing the I.T. purchases and assets of our various subsidiaries, each of whom made their I.T. purchases in different places. Now, CDW helps me consolidate our purchases, allowing us to save time and money." Constellation Energy currently is using a CDW@Work personalized Web site for customized procurement services, enabling the subsidiaries within Constellation Energy to order, ship and manage I.T. purchases under one account. The extranet and CDW's same day shipping capability have reduced order cycle time and produced a drastic improvement in product delivery time. The various business units of Constellation Energy now benefit from speed, accuracy and reduced total acquisition costs for I.T. products. "Constellation Energy is a proven industry leader, and its willingness to consolidate its I.T. purchasing will improve its return on investment," said Harry J. Harczak, Jr., executive vice president - sales, CDW. "This relationship with CDW is a great example of how customers are benefiting from CDW's capabilities in streamlining their I.T. purchasing and improving their overall productivity and technology performance." About CDW CDW® (Nasdaq: CDWC), ranked No. 381 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 APC, Apple, Cisco, HP, IBM, Microsoft, Sony, Symantec, Toshiba and ViewSonic. CDW distributes contracts to end users for customized and standardized on-site services supplied directly by providers such as HP Services and Unisys and for training programs provided by firms such as KnowledgeNet and Productivity Point International. CDW was founded in 1984 as a home-based business and today employs approximately 3,700 coworkers. In 2003, the company generated net sales of approximately $4.7 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 more than 100 factory-trained and A+ certified technicians on staff. Additional information can be found by visiting CDW.com.