Strange Computer Crash Problem

[chua]

My computer starts to crash in a strange way in recent 1+ year. The features are:

- whenever it crashes, the screen freezes and the HDD led is on
- I need to manually turn off the power supply to reboot the computer. If I use the reset button, it won't work and the computer will give a message like "can't find a bootable media"
- the crash occurs almost randomly - during playing online game, opening a website, starting Winamp or scanning the hard disk. Fortunately, the crash is infrequent (may be 1-3 times per day, mostly once). It can occur at the beginning of the computer session or at the end of it (certainly not only when the CPU is under heavy workload)
- During this period, I have tried the followings: replace the hard disk (from IDE to SATA), updated motherboard driver, open the computer case (for better ventilation), reload Win XP and change the display card but the problem persists

Please help to solve this puzzle.

My PC's configuration

Pentium 4 2.6 GHZ
Intel 865 PERL
1 GB Geil PC3200 DDR Ram
Nvidia Geforce FX5200
Maxtor 250 GB hard disk (SATA)
NEC DVD_RW ND-3500AG (IDE)
Power Supply at least 350W
WIn XP SP2

 

[Spartan109]

maybe your psu is under powerd,thats wut it looks like to me

 

[blackjack]

What happened when you ran the computer with the case off? what is your CPU temperature when running? it could be a heat issue or a driver confliction between to programs,think back to when it all first started, did you start using any new software? that answer might hold the key to your problem.
When you reinstalled windows did you install and update you AV and FIREWALL next ruling out any threats that may be creeping in, run a spyware program to see if that picks up any Trojans/malaware.

 

[chua]

Thanks all for the replies.

The problem has been there for some time and I could not recall any particular triggering event. I have been using antivirus, anti-spyware program and firewall all along and cannot identify any problem so far.
Personally, I suspect hardware problem is more likely but cannot figure out which part is responsible. Of course, I can get another set of hardware and try out each component one by one but that can be quite tedious.

In fact, I have run the computer with the case off in these 2 days and so far no crash experienced (CPU temp is around 40 c). However, I have tried this method before and the computer would still crash. See if I am more lucky this time. I have also turned off the hyperthreading function of the CPU.

I just wonder does the way the computer crash (screen freezes / need to turn off the power to restart/ the prompt "insert a bootable media") gives any hint to the potential cause of the crash.

Hope this puzzle can be solved soon