Ctrl+Alt+Del => Task Manager, check how many processes, and % free physical memory.
Do you feel your computer is running slow? (Start up, open applications, ect...)
Your system can reach 12k score in 3dmark 2006 with default settings.
I'm running Vista 64 bits, right now I have few IE, Msn, Windows media, KIS.
Total processes = 60, 50% free memory. (2GB)
And I have reasonable score in 3dmark 2006.
If your OS is too messed up, you might want to re-install OS. A clean copy with new drivers for everything.
AMD Phenom 9750 X4 @2700 + CNPS9700 NT.
AM2 M2N32 SLI-Deluxe Bios 1903
Corsair TWINXMS2 6400 @ 900MHz 5-5-5-15.
eVGA GeForce 8800GT 512MB x2 SLI @700/1000
3x250GB Seagate 16MB cache RAID 0.
3DMark 2006 score: 13689
3DMark Vantage: P11523
Windows Vista 64 Bits.