What would cause a computer to repeatedly reboot?

Generally there are 2 causes of a spontaneous reboot....

If Windows doesn't list any error, such as in the log files http://www.topbits.com/how-to-read-windows-log-fil...

AND if your antivirus is not alerting you to anything....

Then the issue is NOT inside Windows, but outside of it.

Anotherwards, you most likely have a hardware issue not a software issue.

2 most common causes are:

Power Supply or electrical surge/drop

or

RAM/Memory errors.

Just about everything else would either not cause Windows to spontaneously reboot OR give you some sort of warning. Even a hard drive failure would typically give you some errors.

Most Hard drives now come equipped with SMART - self monitoring and reporting technology. If the hard drive detects an issue.. it reports it to the BIOS and Windows finds out about it.

Sound cards don't usually cause spontaneous reboots.. Windows can continue to work without sound.

Video issues usually just cause blank screens.

Try this...............

Unplug EVERY unnecessary device from your computer besides the keyboard, mouse, LCD monitor, and hard drive.

That means removing cellphones, external hard drives, MP3 Players, USB hubs, extra lights, extra fans, speakers, USB printers, even the DVD/CDROM player.

Make sure nothing is touching the keyboard, I had one customer who had a book resting on the keyboard.

Shutdown the computer. Remove the power and flat IDE cable from the DVD. You'll have to open up the case to do this. Make note of how the fiant red line on the IDE cable is orientated. It needs to be put back the same way. Usually the red line (pin 1) is on the side where the power connector is located.

If it was plugged into a surge supressor, tempoarily remove it.

We are trying to eliminate as many possibilities just to be sure.

Reboot it. -- See if the issue gets worse or better.

If it seems stable and stays on for longer then usual... add back 1 device at a time. For the DVD player, you'll have to shut it down 1 last time to reconnect it.

Try running MemTest x86 on your Memory. You'll need to burn a CD of MemTest to do this. it is a freely available program online used by IT experts to test your computer's RAM.

If you have a Dell or HP, your computer may have some built in diagnostic programs that can be acceessed by hitting F2 or F11 or something. Watch the computer screen carefully as it boots up, it might flash a message indicating which button to push.

It may simply be that your power supply ins't strong enough for all the stuff you've added onto it. If your powersupply is an old 250 or 300W unit, it may ONLY be able to run the computer. Adding a 2nd DVD burner or MP3 players or a USB hub, etc. might be too much for it.

Even if it is a 400W or 500W, depending on the Graphics card and CPU you are using.. you may need a 600 or 700

Unplugging things will allow you to reduce the load on the power supply and see if that solves you issue.

Lastly, if you can't isolate the problem, you may need to take it into a computer store. I prefer locally owned stores. Geek Squad charges WAY too much in my opinion.

Computer Continually Reboots

First thing you should try: Right click on My Computer > Properties, click on the Advanced tab. Under "Startup and Recovery" click Settings. Under "System failure" make sure the Automatically restart box is unchecked. Next, go into My Computer. Right click on your hard drive > Properties > Tools tab, click on Check now. Make sure that both boxes are checked and press Start. Good ways to start, and see if there's a problem with the hard drive too.

If the reboot program is in the startup options, when booting up press f10 or f8 or f2 (forget which) and boot into safe mode. Then go to start run, msconfig, go to start up, and take out anything suspicious.

Most likely overheating. Start by blowing out all the dirt and dust with canned air (not a vacuum cleaner or air compressor). (This is best done outside.)

Overheating, virus infection.., bad luck, jinx... just to name a few, but th first two would be my choice

One possibly is that the HD is bad, or going bad. I had that happen to me, and ut was the HD.