Installed Warcraft 2 BNE..... All 3d games on my computer run with lag?

Hey guys, I'm new here, so bare with me.

The other day i installed warcraft 2 bne, yes, the old blizzard RTS, for old times sake. I played it flawlessly for about an hour.

Later on that evening, I tried to load up warcraft 3. Whenever i moved my mouse on a 3d menu, i experienced lag. This same problem carried over into gameplay, whenever i moved mouse or the game camera. This problem carried over into world of warcraft... whenever i moved, my video became choppy, extremely low fps. Finally, I tried running counterstrike source and whenever i moved or looked around, my fps shot way down. It really made me wonder what was going on when i was even able to spectate people and watch them move/look around without lag or fps issues.

I ran a scandisk on one of my hard drive that has all my games and personal files installed, not even my video drivers or any windows files. I let this scandisk run all night and after waking up in the morning, my computer ran good as new.

However, after turning off my computer that night and starting it up again in the morning today, my problem persists. I did the same scandisk with no success. I defragged my other drive with system files and such and am about to scandisk it. Video drivers and directx are both updated and compatible.

Anyone have suggestions?

System Specs:
Windows Xp pro 64 bit
Asus P5n32-e motherboard
Duel Xfx Nvidia 8800gtx in SLI
Intel Core 2 duo 2.4ghz
4gb Corsair Ram

I am not over clocking and haven't over clocked this rig before. Its almost 2 years old now and has never had any major complication that hasn't had immediate and obvious solution. Thanks for everyones time, please help if you can.