Back in December I upgraded to 8.1, not expecting much difference from 8. Wrong. It took a turn for the worse, actually. Let me list some problems here.
d3d9.dll (enb mods for example) is seemingly "blocked" and ENB no longer works
My MIDI software keeps getting unregistered by the computer and I have to manually uninstall it
RadeonPro doesn't work for 8.1, however, I think I've heard of a newer version that had its name changed.
Don't know what Microsoft was thinking of when releasing this. I'm going to see what happens when I completely disable UAC. I'll edit when I see the results.
UAC did nothing for rFactor, but I think RadeonPro just wasn't running with UAC enabled or running w/o admin.
MIDI software will take some time.