Computer Restarts Itself Category: Hardware

12:10:00 AM |

"My PC running on Windows XP frequently restarts it self for no apparent reason. Any files or internet pages I have been working on are lost. The PC reboots to the desktop and I have to redo all my work. Any ideas please?"

Baby, It's Hot in There

Sometimes this can be caused by an overheating situation. Itunes, RealPlayer, Windows Media player, etc. require a lot of processing power to decompress and decode music files, which can cause the processor or hard drive to get hot.
If your CPU is running at over 60 degrees (C) you might be at risk of burning it out. Some systems shut down automatically when the temperature reaches an unsafe level. Every few weeks I open my system unit and clean the fins on the heat sink that sits under the CPU. When they collect dust it restricts the airflow and prevents proper cooling. You can use a can of compressed air (look at your local office supply store) or an old toothbrush. I just did that on my system and the CPU temperature dropped by ten degrees!
Download the free Speedfan utility and it will tell you the temperature at which your CPU and hard drives are running.

Memory Fails Me...

If you determine that overheating is not the problem, the most likely suspect is bad memory. Trying to access a bad spot in your system memory (RAM) can cause the computer to freak out and restart. The best way to find the culprit is to pop open the system unit, remove (or replace) one RAM stick and see if the problem is solved. Run your system for a while and if the problem goes away, you win! If not... lather, rinse and repeat for each RAM stick until you find the one that's misbehaving.

Don't Do Me Any Favors

There's a setting buried in Windows XP that tells your computer to restart when a system error occurs. If you turn off that option, you may solve your automatic reboot problem.

  • Click Start, then open Control Panel
  • Click Performance and Maintenance
  • Click System
  • Click on the Advanced Tab
  • Click Settings in the Startup and Recovery section
  • Uncheck Automatically Restart in the System failure section
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 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.