Computer restarts suddenly

[u_sidiq]

Hey Friends,

I had P-IV system 5 years old, last month my hard disk drive damaged. For that i changed new hard disk drive of 7400RPM, i installed XP.
System produce too noisy and after some times it's restarted, so pls guide me to solve the prob's.

 

[Ijack]

Could be most anything, but I'd suspect that it's hardware related. A failing psu possibly.