Disable auto-restart in Windows 7?

For some reason my laptop is able to perform Windows updates automatically WHILE IN SLEEP MODE. I left my laptop in sleep mode (close lid) before i went to bed yesterday, and this morning when I came to start the laptop for some reason the laptop is turned on! The screen was the log in screen, and after I logged in there was a notice in the task pane saying "windows has finished installing updates and restarted your computer" or something like that. Now I don't give a damn how the hell my laptop was able to install updates while in sleep mode, but does anyone know HOW TO DISABLE AUTO-RESTART? I had unsaved work left before I left it in sleep mode, and the computer chose to auto-restart while I was sleeping and I lost all that unsaved work! Thanks.