Before you do Format, If you have more than one stick of RAM installed on your M/B.
Try taking all but one of them out,Turn Computy on,If it still Crashes, Install another stick in its place , (1 Stick RAM installed at a time)
See if you can find the stick causing the prob.
Most times when freak crashes like this happen,RAM is at fault.
I've even had BSOD and other wonderful error messages pop up and after two days of trying to figure it out,was ready to reFormat,then i took out my sticks of RAM and found a film of dirt on one of the RAM slots on the M/B.Once cleaned computy ran fine without errors.
Weird eh? Go figure , (Mental note:Must keep inside of Computy Box clean)
Anyways just give it a try ,you never know might save you a reFormat,Hopefully.
Catcha,
Billy.