Thanks Tom,

There are not fixed time when it hangs. But usually with an hour time. Once it hangs, when I re-boot the computer, it hangs even faster. Sometime even during booting phase.

I have just re-format my computer recently, but it doesn't help.

From the serviceman who are trying to repair my computer, he claims that when each component is fitted up with other parts, example, my motherboard with his graphic card, harddisk etc, it works perfectly. So is my harddisk, graphic card, etc.

However, when all my parts are put together, the system will have problem.

Could something like what i said be happening? Cuz, I would like to have some second opinion on this. Thanks.