Hi
I would advise editing to remove your email address unless you like spam
your Windows 7 driver is probably located in c:\windows\system32\drivers
but I would goto Autocad web site and look at FAQ for install problems as Autocad install would know that location.
Problem maybe Autocad version specific.
You also need to look at Autocad compatibility for different graphics cards & drivers
you need to state if 32bit or 64 bit Windows 7 and Autocad version and Graphics type before anyone can really help you
best of luck
regards
Mike Barnes