Hmm. This is why XP SP2 has been in beta so long, because it breaks apps. Developers have been aware of this now for several months, like at least 6. There are definitely some gotchas to it, but I have installed it on 10 systems without a hitch, everything still works fine. So it can most definitely depend on the system, drivers, devices, etc.. Before you upgrade, perform a complete backup, update all your device drivers to the latest versions and same with your apps. Regards, Paul