0001193125-07-168162 DEFA14A 2 20070801 20070801 20070801 CDW CORP 0000899171 5961 363310735 IL 1231 DEFA14A 34 000-21796 071016661 200 N MILWAUKEE AVE VERNON HILLS IL 60061 8474656000 200 N MILWAUKEE AVE VERNON HILLS IL 60061 CDW COMPUTER CENTERS INC 19930322 DEFA14A 1 ddefa14a.htm DEFINITIVE ADDITIONAL MATERIAL GRAPHIC 2 g36801snap0002.gif GRAPHIC