Which computer part....

[mol3000]

After restarting for no reason for about 2 years now my computer has finally had it. I notice today i had some crazy error messages that i didnt recongnize and i restarted it. Well then after it restarts it gets to the windows start screen then it just restart again. Well i thought it was a hd problem because i had a virus on there a few weeks ago but thought i had it all off. So to make sure i stuck another win xp hd in and the same thing happens again, rather i go to safe mode, safe mode with network or regular mode what it does is get pass the bios and looks like it want to start windows (not always showing the windows start page) then just keeps restarting. I tried a 3rd hd with windows vista on it and again it passes bios and starts the o.s. then restart computer. I took each mem module out and even switching them to see if it was something wrong wit the mem but the same things happen. Can someone please help because i dont have the money (even though i want another one) for another processor and motherboard plus memory.

[redwudz]

I'm going to assume a hardware problem.

You can try to boot after each one of these:

One thing you can try is to unplug the computer and pull the BIOS battery for a few minutes, then replace it. That will reset your BIOS. You will also lose your custom BIOS settings, so you should record them. Check your voltages in BIOS too, if your MB shows them.

Check all the internal cables and cards to see if they are seated properly.

Unplug all your drives except the boot drive and pull all your PCI cards except the video card.

Substitute the video card.

Substitute the power supply.

If you got this far, you likely only have the CPU or motherboard left if you have ruled the memory out.

[ranchhand]

Memtest86+ is free and good for checking your memory-Google it.