Computer turning off?

Hi all -


I'm fairly new to the Mac world. My issue is that when I don't put the screen down to the put the computer to sleep when I go to bed, I wake up and the computer has been restarted. This is very irritating sometimes because I'm often in the middle of a project and have all my windows organized a certain way. Or sometimes I have a few webpages open I want to come back to the next day. There's no way it overheats... its way too new and I don't really run any large programs anyway. I looked in the system preferences and couldn't find anything. Any suggestions?

PS: I have a MacBook with 4 GB ram and I haven't added any hardware. The computer is less than two months old.

Go up to the menu bar and click on the battery icon. Then click on Energy Saver Preferences. Then on the bottom right press the Schedule button. Make sure there are no check marks next to shut down at so and so time.

Nope, no checkmarks.