Can i use a vista driver with windows 7

You'll have to be more specific to get a good answer, what are you trying to run, and what are the drivers for?

I can say in general that I have used some vista drivers with success, but that doesn't neccisarily mean that all drivers will work.

^+1. In general, drivers(like graphics, sound, printer,etc) for Vista works on Windows 7. HOWEVER, you may still run in to problems for things like printers, cameras,etc.