QUESTION My PC has recently begun crashing and restarting itself without warning. I haven't installed any new hardware or drivers, and the crashes aren't triggered by a particular program – often they happen when the PC is idle. How can I fix this problem, please?
HELPROOM ANSWER The problem you describe is often caused by overheating problems, which can be caused by a build-up of dust that clogs up the fans and blocks essential ventilation. Typically, you can check the internal temperatures by entering the Bios and looking for a menu that contains fan-speeds and temperature information. This should show you if a fan has failed, or if temperatures are sky-high.
Alternatively, download and install Speedfan.
If you're lucky, you'll be able to resolve the issue without opening the case, simply by blowing dust away from the fans. You
can use a compressed air canister to do this, but be sure to first turn off and disconnect the PC from the mains.
In more extreme cases, you may find that enough dust has entered the case to require you to open it up. This is usually as simple as removing a couple of screws at the back and sliding off the panel.
Assuming that you're happy to delve inside, you should carefully examine and clean each cooling fan. While inside, also check the processor cooler, which is prone to dust build-up.
Following a good clean, your computer should start to operate at a lower temperature and the random crashes should stop. You may find that the PC operates more quietly, since the thermostatically controlled fans won't need to run at full speed.
To prevent this happening again, you may like to place some dust filters inside your case, which can trap the dust before it gets to the PC's internal components.
You'll know if one or more fans have stopped working because your PC's Bios will warn you with an annoying bleeping noise. It is possible for these warnings to be turned off, however, so it's worth checking to be sure. Faulty fans are easy to replace and relatively cheap to buy. You could also take this opportunity to purchase a quieter fan.