0000899171-03-000028 4 1 20030331 20030331 ZEMAN GREGORY C 0000938779 DIRECTOR 4 4472 WELLINGTON DR LONG GROVE IL 60047 8474656000 CDW COMPUTER CENTERS INC 0000899171 5961 363310735 IL 1231 4 34 000-21796 03631145 200 N MILWAUKEE AVE VERNON HILLS IL 60061 8474656000 200 N MILWAUKEE AVE VERNON HILLS IL 60061 4 1 form_4gz033103.htm GREG ZEMAN' OPTION EXERCISE 3-31-03