Windows restarts without warning.

12:55:00 AM |

This document is for computers that are restarting or rebooting by themselves and not computer's that turn off and remain off.

Software issue or error
Errors generated by software programs can cause a computer to reboot unexpectedly or without warning. If you are running Windows XP see the below section "For Windows XP users" before continuing.
If you are not running Windows XP or following the below steps still cause your computer to reboot without warning. Boot your computer into Safe Mode, and let the computer run in Safe Mode.
If the computer is still rebooting in Safe Mode the issue is likely not software related but something else, skip to the next section. If the computer is not rebooting in Safe Mode it is likely you have software related issue. We would recommend you run through the basic troubleshooting section for your operating system.

For Windows XP users
Windows XP is designed to automatically reboot each time an error occurs such as a BSoD. Although this may be nice for errors that do not occur often, users who have a re-occurring error may wish to identify the error to troubleshoot it. Below are the steps on how this feature can be disabled and enabled in Windows XP.
  1. From the desktop right-click on My Computer.
  2. Click the Properties option.
  3. In the System Properties window click the Advanced tab.
  4. In Advanced click the Settings button under Startup and Recovery.
  5. In the Startup and Recovery window uncheck the Automatically restart check box.
  6. Click Ok.
Now if the computer generates and error it should not automatically restart and enable you to display any errors your computer may be experiencing.

Hardware issue or error
 Some of the below steps require you open your computer. While in the computer, be cautious of ESD.
Any failing hardware component in your computer could cause your computer to unexpectedly generate an error or reboot without warning. If you have recently attempted to add a new hardware device, remove that device to make sure it is not causing your issues.
Make sure you are not encountering any hardware conflicts by viewing Device Manager for errors.
New drivers can also cause this issue, if you have recently performed any hardware driver updates you may wish to try an earlier version of the drivers. Additional information and help with computer drivers can be found on our drivers page.
If you have updated drivers and removed any hardware that could be causing this issue and continue to experience random reboots, it's possible that the memory is bad in the computer.
  • How can I test my memory to determine if it is bad?
Finally, hardware devices that are not installed properly in the computer can also cause random reboots. Make sure all the cables and expansion cards are connected properly to the computer. The best way to determine this is to disconnect and reconnect all cables and expansion cards.

Computer virus
Computer viruses such as the blaster virus are written to reboot your computer without warning. Usually these viruses will make the computer reboot ever 5, 10, 15 or 30 minutes after the computer has booted.
If you believe your computer may be infected with a virus or are uncertain if your computer is infected with a virus make sure your virus scanner definitions are up to date.
  • How do I update my antivirus program?
Update through antivirus program
The majority of new antivirus programs (programs or computers purchased after the year 2000) enable users to update their antivirus program through the software. Open the Virus program and look for "Update", "Check for updates", "Live Update", or something similar. Below are some examples of how a user may update their antivirus program.
  • Microsoft Windows users running recent versions of McAfee can double-click on the Vshield icon in their Systray and click "Check for VirusScan update" to check for available updates.
  • Microsoft Windows users running recent versions of Norton can double-click on the Norton icon in their Systray and click the "Live Update" to check for available updates.
Update through antivirus web page
If your antivirus program does not include the ability to update your virus definitions through the software program or you wish to download your definition updates directly from the developers web page, make sure to first identify what version you are running and then visit your manufacturer's web page below to update your software.

Heat related issue
Many computer today are designed to turn off or automatically reboot if the computer, processor, or other device in your computer gets to hot. If you have heard any abnormal noises coming from your computer recently such as a high squealing this could indicate a fan may be failing in your computer.
First, verify the fan on the power supply is working by examining the back of the computer and seeing if the fan is moving and moving smoothly. For all other fans in the computer you will need to either open the computer and verify all fans are working, e.g. processor fan and case fan.
Tip If your BIOS monitors the RPM of the fans enter CMOS Setup and verify it does not report any errors.
  • What temperature should my processor be running at?
Depending on the processor, the manufacturer, how fast it runs, where the sensor is located, and what programs it is currently running will determine the temperature of what the processor should be. However, this document should give you a general idea of what the processor should be running at as well as what is acceptable and what is not.
The majority of today's desktop processors should not exceed temperatures of 95C and most will run between 70-90C. Below are some charts of many of the processors and their average temperatures. Keep in mind this is only to give our users a general idea of what their processor should be running at. If you believe your computer is running to hot, you may wish to skip to the bottom of this document for additional details on how to get exact information about what your processor should be running at.

ProcessorsAverage temperature
AMD Athlon90C - 95C
AMD Athlon6465C - 70C
AMD Athlon64 Mobile95C - 100C
AMD Athlon MP90C - 95C
AMD Athlon XP85C - 90C
AMD Duron85C - 95C
AMD Opteron65C - 71C
AMD Sempron90C - 95C
AMD K560C - 70C
AMD K665C - 70C
AMD K6 Mobile80C - 85C
AMD K7 Thunderbird70C - 95C
Intel Pentium II65C - 75C
Intel Pentium III60C - 85C
Intel Celeron67C - 85C
Intel Pentium Mobile100C
Intel Pentium Pro80C - 85C

How will I know if my processor is running too hot?
If a processor gets too hot you will notice one or more of the below situations. Often these issues will be encountered when running programs or especially when playing an advanced game.
  1. Computer runs much slower
  2. Computer restarts often
  3. Computer randomly turns off
Continuing to use a computer that has a processor that is exceeding its temperature will reduce the life expectancy of the processor.
Note: It's possible that with some computer configurations that the thermal sensors may not be positioned in an optimal location, causing the temperature to be reported cooler or hotter than it actually is. If your temperature is close to exceeding the maximum temperature or you are experiencing the above issues, you may want to continue reading the below recommendations for getting your computer cooler.

What can I do to get my processor cooler?
The cooler the processor runs the more performance you are going to get out of it. Therefore, if you're looking to overclock your processor or if it's getting too hot, you may need to consider any or all of the below recommendations.
  1. Improve computer's environment - Make sure the computer is running in a good location. The computer should not be in an enclosed space such as a drawer or cabinet unless there is plenty of ventilation such as the back of the drawer or cabinet is removed. The computer should not be in a tight space, there should be at least a two-inch space on both sides of the computer as well as in the front and back of the computer.
  2. Verify fans - Make sure all fans in the computer are properly working. Some motherboards and computers have fan monitors that will display the RPM of each of the major fans in the computer and if they are operating properly. Otherwise, you will need to check each of the fans and look for any spinning issues or listen for any abnormal noises to determine if the fans are properly working.
  3. More fans - Consider installing additional fans into the computer. Almost all computers will come included with a heatsink and fan, as well as a case fan. However, most cases will have the availability to install a second case fan that can help bring in additional air and help keep the computer cool. Computer enthusiasts and many overclockers may also create their own air ducts with fans to help bring in additional air or take out more of the hot air.
  4. Better fans - Many computers and processors will come with cheap fans to help bring down the overall cost of the computer. Installing improved fans or heatsinks that can move the heat away from the processor better and faster can keep the processor cool.
  5. Alternative solutions - More advanced users or users who are overclocking may also wish to consider alternative solutions such as water cooled solutions to keep their processors cool.
My computer displays the temperature in Fahrenheit and not Celsius
Visit our JavaScript Celsius to Fahrenheit converter to convert a Celsius value into Fahrenheit.

Issue with operating system
If after following each of the above recommendations your computer still continues to reboot it is likely that you are experiencing a Microsoft Windows operating system related issue that cannot be explained. To help make sure this is the case try the below steps.
  1. Reboot the computer and enter CMOS setup as the computer is booting.
  2. After you have loaded the computer in CMOS setup let the computer sit.
If the computer does not reboot while letting the computer sit in CMOS it is likely that you are in fact experiencing an issue with Microsoft Windows and it is recommend that if you have followed all of the above recommendations that you reinstall Microsoft Windows.