I'd tried running Spearhead on the MS default drivers for my 6600GT. It was REALLY clunky and slow, totally unplayable. So today I installed the latest nVidia drivers and found that Spearhead would not run at all, just kept blackscreening when you tried.
I downloaded and applied the nHancer 2.11 Vista version as per
Sotko's suggestion and that seems to have fixed it perfectly. The game runs a lot smoother and looks like it will be playable once I have all my maps and mods ported across.
That's a neat tool. Certainly did the business for me.
:sm1: