Quote: Originally Posted by
frozenrat
You can usually press your power button just once, and it will shut the system down, and you won't lose any data or anything. (Unless, you hold the button to force shutdown)
What frozenrat means, is try turning your Pc off from your power button instead of going start > shutdown > ect. See if that works instead.
If it still happens, do what mygearis suggested and check your BIOS settings. There is a chance that it is getting a critical error while shutting down, and your BIOS has a setting which reboots the PC in the event that this happens. Hence, it keeps rebooting.