PC freezes without warning

[moshel]

since last week a very odd thing is happening in my pc.

while im working, the PC just hangs without warning, i am not even using something heavy, just the normal opera or utorrent.

when the pc hangs, the mouse pointer also freezes and the keyboard also dont work. all i have to do is give a long press at the start button to make it shut down.

when i restart it, there is no scandisk, the pc starts normally and i dont even get a message saying that "your pc has recovered from a serious error". its starts as if nothing happened.

btw i use XP. and this thing happens once in a day. either in the morning or the evening (those times only i start my PC).

pls tell me wat m8 be the problem.

thanks.

P.S. one more post required to reach 500! yippee.

[pimpom]

There is more than one possibility:
Bad sectors - run surface scan.
Bad memory - test with memtest86.
Loose connections or defective HDD cable - check or swap.
Overheating - accumulated dust or defective fan.
Defective PSU - swap with a known good one if possible.

[realdan]

SMPS/power supply please