supreme Commander using only 1 core???

Today after I installed the first time supreme commander and tried it out on the first level I was getting about 60fps on average, I had planned to make a clean installation today and so I did (thought i'd yield even better results aswell), to my surprise I've formatted and installed windows XP twice and Vista once and on XP I keep getting the same results now (about 30-40fps), so I opened task manager and found out that only Core#1 was in use, on vista on the other hand it worked just fine (as far as the use of both cores, but I have a series of issues with vista drivers so that's not a viable option for the time being).

I just reinstalled XP and keep getting the same results as before (using only one core), and the only things I have installed are the motherboard drivers and both service packs.

I do recall installing a microsoft dual-core patch before (that was on my original installation) and changing something in the registry from a guide in gamespot, and I tried redoing what the guide said but it didn't work.

Anyone got any ideas?

CPU = C2D E6400 (never overclocked)

Yeah I tried that last night on a desperate attempt, didn't work

okay... ill try

EDIT: May sound stupid... but how do I uninstall it? I can't find it anywhere on Add/Remove programs list.

Did you look on the GPG's forums? There's a thread about dual cores...