For the last few weeks my PC (pretty old P4 with Windows XP SP3) has been crashing randomly. It just suddenly reboots instantaneously. It feels hardware-related but I wasn't able to determine whether it's software or hardware that causes it. I did notice a pattern though: it's more likely to crash whenever I copy a lot of files over network or have uTorrent running, but sometimes it crashes when I am not doing anything with it.
Copying files from it over the network causes it to crash within 1 to 10 minutes almost every time. Using torrents causes it to crash every 1-3 hours. With neither of those taking place, it crashes every 24 hours or so.
I have ruled out the following probable causes:
- PSU (I bought a new one and turned off most of the drives so the power is sufficient 100%)
- Bad HDD or interface cable on my SATA disk from which I was originally copying the data over network (bought new SATA cable and later yanked out the HDD completely, PC still crashes without it)
- Video adapter (AGP slot is now empty, using the onboard VGA at the moment)
- Network adapter (removed it from PCI, using onboard LAN)
- CPU (I think: I changed the thermopaste and its temperature is below 50C)
- RAM (I think: I ran Memtest86 and it didn't show any errors)
At the moment I only have only one system HDD and DVD drives, a mouse and a keyboard plugged in.
The fact that it crashes more often when I use the network extensively makes me think that perhaps it's software related (I removed the network adapter from PCI and now am using an onboard one, so network hardware is unlikely to cause problems). I am now pondering a system reinstall but it's not a pleasant solution so I decided to ask whether there are any better ideas first. If someone can share a good diagnostic tool it would be great because I didn't find anything good.
Note: the motherboard is actually ~4 years old as I replaced it back in 2007.