My Oblivion is running slow as well, I know the solution is a reinstall, windows really needs it every so often no matter how much cleaning you do, I'm putting it off as long as possible though, it's a real headache.
lol, unless you load the GPU drivers in safe mode the GPU won't be used. In fact I think you wouldn't even scratch the surface. So it surprises me how you got CoD to run?
You can enable drivers to be loaded within safe mode, also services can also be loaded. The default safe mode will NOT allow you to run any type of DIRECTX game or anything requiring drivers.