I own a Toshiba Satellite L645D-S7040, when i use my Laptop it will completly freeze randomly without any reason or warning. when it freezes nothing will move (mouse) and the is frozen in time. any program that was runing at the time is also frozen in the middle of what ever task it was doing. like if i was watching a video it would make a high pitch scream until i restart it. normally it freezes after 10 to 30 minutes after start up and at time it could take hours to days to freeze. After the freeze i check the event logs and the only thing posted is the fact that i shut it down. i even did a factory restore and it still does the freezing. and yes windows 7 is the stanfard OS i the laptop. it is only about 14 months old. i am thinking of buying a new hard drive but i would rather solve the problem then buy a hard drive.