Computer randomly turns itself off

[nicholas_t]

Turned on my pc again a few days ago and this time when it turned itself off a red screen came up for like 1 second. Since the red screen of doom has come up my computer hasn't been able to start up. It will just do the sound it makes when its about to turn on for like 2 seconds then gives up. My cd drives light up but thats about it.
My keyboard and mouse which are connected to my pc still work and have their lights on.
Does anyone know if its my harddrive for sure? My cousin is coming around this weekend to have a look at it but I just wanna hear some advice

 

[peterhuang913]

The CPU could have a problem or the heatsink is getting too hot.