Question : Laptop shuts down after 25 seconds of boot up

MY laptop is a ABS gaming laptop. Had it for 5 years.  Suddenly it shuts down after 25 seconds of boot up.  I removed the battery and tried working off the ac plug. Still the same problem.  I can enter the bios and the system will stay in bios forever (does not shut down in bios).  I thoguht it may be a software problem with windows, so i tried to use the system restore disk, but after the system restore disk runs for 25 seconds, the laptop shuts down.  Any other action i do causes the laptop to shut down in 25 seconds (boot to safe mode, safe mode with networking, boot to system recovery partition... all result in laptop shut down.)  the only thing it seems to not shut down the laptop is going into the bios.  Need help.  Please.  Thanks, Anthony

Answer : Laptop shuts down after 25 seconds of boot up

25 seconds seems a little too fast to be a heat issue BUT heat could explain it.  BIOS takes up almost no cpu time whereas booting runs the cpu at nearly 100%.  Can you hear the fan running and feel the air moving through the system?