Computer Restarts Itself

Note that this may prevent the system from restarting, but it can also mask the true problem. As an alternative to this measure, consider what has recently changed on your system. If you have installed new hardware or software, remove it and see if the annoying restart persists. Sometimes downloading the latest driver software from the manufacturer's website will fix hardware incompatibility problems that cause restarts.

Computer Restarts After Download?

Some folks have written to me complaining that their computer automatically restarts itself after every download. And interestingly, most (if not all) mentioned they were using the Firefox browser. If you are using a download manager or download accelerator, this could be causing the problem. Check all the settings in the download manager and tweak if necessary. Or get rid of the download manager and see if the problem remains.

This can also be a virus or spyware problem. I suggest you go through your Control Panel / Add or Remove Programs list and remove any programs you don't need, then run thorough anti-virus and anti-spyware scans. It could even be your anti-virus program fighting with the browser or download manager. Switching to a new anti-virus might help also. See my recommendations for the best free anti-virus software for help with that.

Other Things to Consider

Failing or under-rated power supplies can also cause your computer to restart at seemingly random intervals. Switching out a power supply is really not too hard. Turn off the computer, open the case, disconnect the power cable from the power supply to the motherboard. Unscrew the power supply from the case, and reverse the process to install a new power supply. A 300-watt power supply will be fine in most computers.

And as one reader kindly pointed out, bad capacitors on the motherboard can also cause random reboots. But unless you're kinda geeky and handy with a soldering iron, it's tough to identify and fix this problem. You can find lots more helpful info on bad capacitors at badcaps.net. For most mere mortals, replacing the motherboard as a last resort will be easier than replacing a capacitor.

I also encourage you to read ALL of the comments below, before you rip your hair out, or rip your computer to shreds. It boils down to this... most restart problems are caused by overheating, bad ram, malware, or some other failing component. It can be difficult and time-consuming to identify WHICH of those things is the culprit. The only good solution is to test each one, in sequence (removing and replacing components if necessary), to identify the problem.