As far as the other questions... I have no idea. It depends on whether the OS created a restore point or not, and where all they stored stuff.
If it made registry changes (I think, not sure), they'll be back in the registry, albeit not on the computer. Although if they made a restore point, they may exist there too, but only if the cam made changes.
The restore point was really made for a one-time thing I think. Install something, bluescreens, use to get back in. Go back too many times and weird stuff can happen. I had to once when I did 10 driver updates, the first ones crashed, went back too far and lost programs and video drivers.
Good luck! (see last post for the if camera can work, try WinXP default drivers, then the company's website)
DISABLE THE VIRUSSCANNER whenever installing software from a CD or doing a driver update (like video drivers, printer, camera, scanner) if you don't that in itself can cause problems!