I think your laptop is dying, have you tried using it without the battery or with a new battery? Your powersupply may be near death or you might want to format your harddrive and re-install windows. it could be any number of things there is just not enough info, when did it start doing this and what had you done to it prior?
Dungeons and Dragons Famous Last Words:
"C'mon DM,let's see some REAL monsters!" And then you turn the corner as the Dungeon Master chuckles... DM: "It hits and... Oh hold on... I need more dice"