Computer locking up

You said it it old and slow pc. First do routine maintenance ie defrag hdd, clean out registry and temp files etc.

you probably need more ram but may be expensive if old pc..

Yeah this may be caused becuase your pc is old . i had a problem with my internet explorer freezing on opening it was down to a virus but if you want to know give it a scan after cleaning out your registry and your hdd. if the pc runs faster after this it could be a virus in ie try downloading firefox

Thanks for the replies, the computer doesn't run slow its very tempremental when booting up, when I first booted up this morning it took a few times to get it up and running but since then its been on all day and no problem, I was thinking it might be a problem with either windows XP or the harddrive, I'm no way a computer buff so I'd thought I'd ask you guys, I only use this comp for the internet. cheers

If u have more than one DIMM/SIMM of memory.

Try removing all but 1 stick of RAM. then try each one in turn. It may be due to memory fault.

Try a fresh install to illiminate Software Issues.

A shot in the dark because more or less the same thing happened to me. I had a PC made out of other old PCs and loaded it with XP. Few times it turned itself off and refused to boot or rebooted at random. I first started by checking the PSU as that was 10 years old and on the weak side. Swapped it with a spare one I had lying around and never happened again.

How old is the PC? And how powerful is the PSU? If you pop the side panel off, you should be able to just about see the rating on it.