0000950137-07-005567 8-K 2 20070416 8.01 9.01 20070416 20070416 CDW CORP 0000899171 5961 363310735 IL 1231 8-K 34 000-21796 07768894 200 N MILWAUKEE AVE VERNON HILLS IL 60061 8474656000 200 N MILWAUKEE AVE VERNON HILLS IL 60061 CDW COMPUTER CENTERS INC 19930322 8-K 1 c14208e8vk.htm CURRENT REPORT EX-99 2 c14208exv99.htm CEO'S LETTER