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My Computer restarts every time I switch it off.

Here's the story: My computer automatically turned on few weeks ago when I was sleeping (I didn't set to switch it on nor tune the registry, etc.), and then every time I try to log off from Windows, it just restarts. Even though I push the power button, it just froze without turning off.

I've looked for many solutions on the internet (including Wake on LAN, unplugged all USB devices, tuned the registry, unchecked the box to avoid restart on system failure, and clean up the dust), but nothing works .

Is there any electric shortage? How can I know? How can I prevent it from restarting due to an electric shortage or software problem?

I built my computer about 1 year ago. This problem frustrated me recently; I hope it doesn't harm the hard disk. I need some help. Thank you very much!

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up vote 2 down vote accepted

Just to diagnose, try unplugging the power button from the motherboard.

This would be my first thought and if the problems stops then there is a problem with the switch and you will either need to replace that or the entire case.

If it still happens, I would next proceed by unplugging everything from the machine other than screen, power and keyboard (hopefully it isn't the keyboard causing this - if you have a basic PS/2, with no multimedia features or other intelligence, use that).

If it still happens after this, I would first look at the power unit to make sure there isn't a short causing it to start up. (I know that the signal is sent to it via a couple of pins on the 2x10/12 cable, but I am not sure if a defective motherboard can actually start a computer the other way round).

Anyway, if you are still having problems AND this never happened before, I think it is possible you have a defective motherboard. Try resetting the BIOS to defaults, however you may have to send it back or get a replacement board.

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thank you man ! thank you! i will try those at home. this is the first time i visit this website, ask a question and have a reply in such a short period. i really really hope this help because it is so annoying and yes this never happened before. – Mark Jul 27 '10 at 3:29
@Mark - no problem and stick around, enjoy the site!... If you need to turn the machine on after you have unplugged the button, use a screwdriver or a jumper to complete the circuit where the button would of plugged in to the motherboard - you only need to touch it very quickly. – William Hilsum Jul 27 '10 at 12:24
Last night, after a few attempt (reset BIOS, unplug everything, whatsoever...) it still doesnt work .....and you know what...... i cant even switch it on this morning lol but at least i know ( happy to know !) it should be the problem of the motherboard or transformer thank you wil! – Mark Jul 28 '10 at 1:22

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