computer fans speed up then pc shuts down

[xguesty]

hi guys so i found one of my old laptops and went to start it and asoon as it gets to the windows 7 screen i hear the fans speed up then the pc shuts down
the laptop is a acer aspire 4741 i thought it might be hard drive but iv tried multiple and same thing, anyone got any idea? i mean surly cant be over heat the computer hasnt been turned on in around a year.

Thanks

 

[xguesty]

also just found out just before the fan starts to speed up the computer completly freezes some times i can get to the window 7 logo before the freeze some times i dont get past bios screen... weird

 

[xguesty]

update so i left it for the night and then tried to start it again this afternoon it made it all the way to the desktop before it froze then restarted now every time i try to restart it freezes earlier and earlier in the boot process, really weird never see anything like it

 

[rgd1101]

sound like it overheating.

 

[hang-the-9]

Heat issue is first thing I'd look at, open the case, make sure everything is clean, clean off the heatsink and apply new thermal paste. May also be a motherboard issue, a bad motherboard can cause what you see with the fan running at high speed.