Computer restarting without any particular reason???

i have a spyware doctor anti-spyware and a AVG antivirus free edition with a zonealarm firewall and a norton personal firewall(its useless so i didn't bother to uninstall it) and my computer recently started restarting all by itself , and when it starts again it would restart as soon as the taskbar appears , i ran a scan and it said that there was nothing of any sort , so why is it doing this??

Computer restarting without any particular reason???hijack this

Usually it's hardware that you just installed is causing windows to crash so the computer restarts your computer to supposedly ''save files''. Remove any hardware you just installed, or any mp3 devices or cameras you have connected. Then restart and see if that works.

Computer restarting without any particular reason???liveupdate

you must have changed the ip of the computer or some thing whcih makes zone alarm restart the computer. Go into safe mode and check

first try

Click start%26gt;click run type in msconfig and then press enter. Goto the start up tab and uncheck everything except your anti virus,click ok and reboot.
You probably just downloaded a program that's incompatible with other programs on your computer. Just start to remove one program at a time until the computer starts running normally (you might have to go in to safe mode to do this). Good luck.
Get rid of your AVG and get avast! anti-virus software, you can download it for free and it works so much better. AVG gave a me a lot of sh*t too.
Few days ago i have same %26 I know its virus problem, so you collected AVG 7.5 or NOD32 antivirus and scan your computer I think your probleam was solved.