Hmmm... Hearing that it works on your Win7 installs actually makes me less happy... Means I got a glitch somewhere.
My bad for not including the fact my install was a "clean" on a reformatted drive. I just played HD musical chairs with existing folders/back-ups before the rebuild.
I did try the install to seperate folder, and the driver roll-back to oldest one on nVidia site, obviously with no effect. I'll try that DX redistributable suggestion next.
Thanks to ALL for your inputs! At least I know it CAN be done at some point so I'll continue on. (Great forum)