Why would my computer automatically restart after "shutdown" and "sleep"?

Question

After my "firmware lost the hibernation information of my Windows 7 computer" I have fixed everything except the problem that the computer now will not shut off.

If I choose "shut down", it shuts down, then waits two seconds and starts back up again.

If I choose "sleep", it goes into sleep, waits two seconds, then starts back up again.

Here's the basic info about my computer hardware / software:

• Asus P5QL Pro Sockel 775 Intel P43 max. 8GB DDR2-1066 ATX
• Intel Core2 Quad Q9300 Sockel 775 2.5 GHz FSB 1333 MHz Boxed 2x3MB L2 Cach 95W Yorkfield
• 2x Team Group TVDD2048M800C5 2038MB (2GB) DIMM DDR2-800 / PC2-6400 CL5 184pin Non-ECC
• Arctic Cooling Freezer 7 Pro CPU-Cooler Socket 775
• BE Quiet System Power BQT S6-SYS-UA-450W Netzteil 450Watt
• BE Quiet SilentWings BQT-T9225-LF Case Fan 92mm 16 dBA 32.6 CFM 1800rpm
• Windows 7

I suspected the network card was waking up the computer after shutdown but its wake-up functionality is disabled:

I looked all around in the BIOS and the only type of wake-up setting I can find is this page, but everything was set so that it would not wake up in any case (however, I can imagine this is the right section since I have read that APM is responsible for "powering down the computer to an acceptable power level when it was not in use"). And this has only been happening since the firmware/hibernation issue I mentioned above where everything in BIOS got reset, so I can imagine the solution lies in finding the right BIOS setting but these all seem to be set correctly:

How can I get my computer to shut down and sleep without starting up again?

Solution 1

This happened to me when I had a bad video card pluged in. I swapped out that card and the problem was solved.

I would recomend removing all add-on cards and usb devices and booting the computer with just a monitor, keyboard and mouse attached. Then if the problem is gone, add one device at a time until the problems comes back. Then you will know which device has a problem.

Solution 2

This was happening to me and i tried evrerything, regedit, and other configurations. i solve it by preesing the clear BIOS button on the board ( the boards that doesnt have the button, remove the BIOS battery for 30 sec.) Trie it, with me it worked.

Ricardo Esteves, From Portugal

Comments

[barlop]

this has many ideas aumha.org/win5/a/shtdwnxp.htm and support.microsoft.com/kb/311806

[William Hilsum]

mactonnies.com/hal.jpg - You cannot turn it off.... Not an answer as I can't say for sure, but I would try unplugging all devices and addon cards so you can try and diagnose this. The first thing I would check is Keyboard/mouse and the wake sensitivity in the BIOS - but this would not really explain the boot on shutdown... Could also be PSU related, but I doubt it as you said it is only since an update. Sorry :(

[MetalMikester]

My PC has a couple of special-purpose USB ports - I can only plug two types of devices (a remote control and an external viewer) in those. Anything else (mouse, microphone, doesn't matter) will almost invariably restart the computer a few seconds after I shut it down. You may want to check your motherboard's manual just in case it has something like that (I have an ASUS P5B Premium Vista Edition - something like that.) It took me a while to realize what was going on. Never had a problem after I left those two ports alone.