PC freezing randomly

[fellah]

My system specs:

Intel Core 2 Duo PRO
Pentium P54C
Corsair XMS2 DDR2 (c6400)780Mhz
NVIDIA GeForce 8800 GT 512MB
X-FI Fatality Sound Card


Now my problem is that my pc is freezing randomly. I have tried various methods like removing the sound card, testing memory, and lots more but was of no use. It was working fine up till yesterday. Can anyone help me on this?

[Rkhon]

Which operating system and drivers do you have and what do you mean by randomly?

[fellah]

Microsoft Windows Vista Home Premium
Intel_Chipset_V9001007
169.21 Nvidia

3 hours and 10 mins was the longest time it worked lastly. It freezes even when working normally or browsing the net

[mv]

Have you done any type of overclocking or tried something similar to that?

Also have you tried reformatting the hard disk or reinstalled any drivers?

[fellah]

No, I have not done any type of overclocking. I have already given a try by reformatting the hard disk and reinstalling the drivers but the problem still persists.