Which driver version did you download the v6.6.1 right? Unzipped ok? (only one for win7)
Are all chipsets and other I/O drivers up to date for your system itself?
What version of win 7 are you running, home/pro, 32 or 64 bit- normal installation?
Sorry for all the questions, but other than maybe have downloaded the v6.3, these drivers should install just fine. Its strange you are getting this error. Is the system memory in good shape?
What is your system spec?