Mike, I am running XP Pro and have had absolutely no problems with WL. I have only been using WL for about a month, but have run 4 contests through it already (3 RTTY and 1 SSB). At present I am only hooked up with a RigBlaster for AFSK RTTY. I plan on upgrading to the RB+ and adding rig control as well. Will see how that goes. Good luck.\ 73, Chris W5CTV