Computer keeps locking up even when doing nothing

[Goneinsane]

Hi, I'm new here, but have grown up with computers all my life. I upgraded to a pentium 4 about 2 years back, and now it has decided to randomly freeze up. Sometimes its when I'm just surfing the web or even if its just sitting there and I'm not on it. My brother who is a computer savvy told me that it is possibly my hard drive, so I got a new one and re-installed windows. It partially was the hard drive, because I ran diagnostics and it said the hard drive was bad. But, my computer is still freezing up and I don't know what to do. My old apartment had a transformer blow to our building three times and I'm wondering if that may have fried something in my computer. I've checked the bios time and made sure that it was set to the same time as my computer and it was. The only other thing that I can think to do is to replace to processor, but I don't want to put any more money into my computer if it's not going to help. If anyone has any ideas or any questions I would be grateful for the help.

[Goneinsane]

This is just a follow up, I went to play one of my favorite games on it, being Unreal Tournament, and I got my computer to run for a good 2-3 hours so I don't really know but any advice would be helpful.

[kc0arf]

Hello,

It is possible that there are power problems. Do you have frequent brown-outs in your place? Do you see the lights dimming here and there for a moment, or perhaps a flicker, and then the computer acts up? You might need a UPS to clean up that problem.

You can also check the system logs to see if any new reports exist in the logs. Perhaps you have some service knocking the system down.

Christian