Alrighty, interesting. I would recommend trying to set UAC to none, and restarting then running again. Also, you can possibly try right clicking the game executable and having it run as administrator.
Otherwise, you might also try installing Direct X's older runtime libraries, possibly DX9, this game user older libraries. If you have trouble finding any of these, I can link them later today when I have some time.
On a side note, I know the game will work on win7 x64 so its a setting or driver issue somewhere! Also, if you have time before this evening if you post your DXDiag on here or message me with it, I will take a look to see if any of your other settings might be causing trouble. (To create a DXdiag hit start -> run type dxdiag -> hit enter, save the output to a text file.)