I had random shut downs and spent two days trying to sort it out. it was only the dicky psu. Get a new one before anything else. Mine only cost £20.
Poor psu's cause weird and wonderful effects to a computer. Computers should be sold with a spare! Psu fail gradually unfortunately.

Hi Techies
this is satya.
i am using windows-xp s2 in my computer ,but it is shutting down randomly, without any msg or warning. can u plz suggest me what to do, should i install windows-xp windows again to my compuetr by formatting d previous one......

I've split this thread as it is a separate issue from that of the original poster.

Does it shut off or reboot? Generally OS errors cause a reboot and hardware problems cause a shutdown.

hi satya, try to re-install first your OS, if it doesn't help then it might be a hardware problem check your PSU and make sure also that your processor fan is working properly.. co'z overheating will cause the system to keep rebooting

I'd start with the temperature check before formating, 80% of the random reboots are solved with that