I have stuttering issues which I really don't know how to resolve. I've not even got past the first cutscene because I want to play it 'properly' without lag/stuttering.

I'm on Win7 and I've tried:
Windows 98 Compatility mode - doesn't work.
Making it use more than one CPU core - doesn't work
Making a Config.ini file - doesn't work.

I know it should work seeing as I regularly play games which are a lot more intensive like TF2 and Portal 2. Any ideas guys?

Oh and I forgot to mention that FRAPS shows the framerate to be usually between 100-200 fps yet the stuttering is still terrible!