I switched to XP and generally had no problems or special setup requirements, except to stop using the LPT port for CW keying. Apparently, NT/WIN2K/XP operating systems lack the necessary kinds of LPT support (workarounds are available and talked about extensively on the reflector). I installed a W5XD Multi Keyer and am very happy with it, but the COM ports should also work for keying. 73, Bob - W3YY