Windows 7 Automatic shut downs?!?!

[kalininety]

whenever i leave the computer running, logged on, about an hour later, it restarts "unexpectedly" - says windows wasnt shut down properly on teh on the boot screen.

when i don't log on, it restarts within minutes.

anyone help?

hp pavillion notebook

 

[joshep_c]

Automatic shut down

My laptop shuts down automatically and I have to wait at least 3 minutes to turn on again. What is happening???????