Not sure if this is the correct category to post in but anyways.
My system specs:
i3 550 (stock)
4gb 1333 Kingston Ram (2x2)
1.5tb Seagate HDD
Zotac GTX460 1gb (stock)
550w power supply
WIN 7 Ultimate (64-bit)
For the past few days my pc has been hanging especially Firefox. PC hangs (including mouse) for a bout 5 seconds then returns back to normal. Firefox hangs every minute. I don't overclock so I hope hardware is not damaged. I'm using AVAST and Spybot which detects no viruses or trojans.
This morning the PC froze and I had to hard reset. PC switched on but monitor displayed nothing. I reseated the CPU (put on new thermal paste) and the problem persisted. I dissembled the GPU, cleaned it out, applied new thermal paste and re-inserted. Same problem. After I reseated the RAM the PC started up again but still with the sporadic freezing.
Unfortunately I don't have extra parts to determine which part exactly is causing the problem and I don't want to buy anything before establishing the problem. My Idle GPU temp is 44 degrees celcius and CPU 30 degrees.
Formatting and re-installing windows is my last resort then I'm totally flabbergasted.
You can have a look at windows event log and see if you can see any errors that can get you closer to what is failing. It sound like your RAM is faulty. try to boot with 1 stick or ram and if that doesnt work rotate and try the other. Windows will boot with 2 gigs of ram.
If it still has problems, then it is still likely that you have a RAM issue. See if you can take the PC to a shop and test with a different type of RAM.