Computer stuttering in Windows 7 - Reformatting doesn't help

Hi,

Specs:
OS Windows 7 Ultimate x64
CPU Intel Core 2 Duo E6600 @ 2.4GHz
Motherboard Gigabyte 965P-DS3
Memory 4 GB DDR2-SDRAM PC-5300
Graphics Card MSI N560GTX Twin Frozr II
Sound Card -
Monitor(s) Displays Samsung T240


PSU Coolermaster 550W
Case Coolermaster
Cooling Stock
Hard Drives Seagate Barracuda 7200 320 GB WD Caviar Green 1 TB




My computer was stuttering badly recently. It runs smoothly in games like FIFA 12 initially, but after a period of time (could be 5 minutes or an hour), the game starts to stutter. FPS doesn't really drop but the game stutters so badly I couldn't even play it. As I exit and try to load Skyrim, the initial loading might take up to 5 minutes, which is incredulous even when loading the world map.

That aside, Firefox was also stuttering whenever I tried to scroll, be it a page full of graphics, a text file or pdf.

All these problems could be 'reset' by restarting my computer but the symptoms just come back soon after.

Thought I might have too many programs installed, so I decided to reformat my computer and reinstall a clean copy of Windows 7 Ultimate x64. Didn't really help though. After installing all my drivers, the problems persist.

I am currently using AVG as anti-virus and didn't detect any rootkit virus or anything.

My CPU temperatures are fairly normal for Core 2 Duo E6600, doesn't go past 60C in the tropics. The CPU loads <10% when idle and max out when playing games. Same goes for GPU. None of them are overclocked. The problems only happen in the past month or so. Encountered no such problem previously, therefore I suspect it could be fault on the hardware part.

Any help would be greatly appreciated :)

60c is like the max temperature for that processor, it might be throttling down to prevent damage, try cleanning the heatink leaving it dust free and apply a fresh coat of thermal insulation material like artic silver 5.