It happens randomly. Literally anytime.
For instance most recently it was when i was playing WoW. Then the time before that i was watching a youtube video.
Additional information : 1) This NEVER happens in Ubunutu.
2) I tried to install windows XP , but it stops at the install at 34 minutes which says "Installing Devices"
Not sure whether either of these are related to my problem , but just some extra info