All you need to do is turn digital signatures off. Basically, Microsoft tried to screw MORE money out of vendors by insisting that a driver has to be "digitally signed" by Microsoft before it should be used, and for this the vendor needs to pay a fee. Most vendors don't bother, and why should they?
Happily, it's easily fixable. Right click on "My Computer" and select Properties, Select the "Hardware" tab and press the "Driver Signing" button. You'll probably find the option selected there is "Block - Never install any unsigned driver software" - change this to the top one, "Ignore - Install the software anyway and don't ask for my approval" then re-install your software. This time it should work fine.