The same drivers are used for both XP and Vista. They will be copied to your PC when you install PicoScope 6.
After installing PicoScope 6, connect your scope to the PC and Windows "found new hardware" wizard should run. You just need to select install automatically.
If you want to specify the file manually, it is c:\windows\inf\picopp.inf
If you are still having problems, please give us a call 01480 396 395