Kolla denna sidan.
http://answers.microsoft.com/en-us/w...b-2935c8c3e108
Testa:
Try this: Press (Windows Key)+R and type in regedit and hit enter. Locate the following key:
Location: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
Double Click on "PowerdownAfterShutdown"
Then,
Change it to "0" if it is "1" OR
Change it to "1" if it is "0".
And hit Enter.
Then restart the computer and after it restarts try to shutdown again. Hopefully this will work for you.
***If this doesn't work make sure you change the value in regedit back to what it was originally***
Eller
I solved this problem on my Gigabyte Z68x-UD3R-B3 motherboard.
1. I updated the BIOS
2. the problem still occurred so I changed the Power Management settings in the BIOS to:
A. disable power on from PCI devices
B. disable power on from LAN
Theoretically both these settings shouldn't have mattered as I believe another setting had to be switched on for them to take any effect. But i no longer have the reboot problem when I shutdown.