for the last while my cpu randomly turns on.  also if my cat brushes up against it while its running it will reboot.  Over the weekend opening a program will bring up a blue screen and reboot.  we have formatted cpu and RELOADED windows xp back on everything will run but while trying to run wow it does the same blue screen.   someone please help.  dont KNOW what the PROBLEM might be.  my only guess would be hard drive is shot.Go to System Properties - Advanced - Startup and recovery settings and uncheck "automatically restart". Next time there's an error the blue screen should stay up. Post the entire contents of that blue screen error here. Also, just as an aside, you don't format a cpu - you format a hard disc this is displayed on blue screen

Blue screen

A problem has been detected and windows has been shut down to percent damage to your computer.

PAGE_FAULT_IN_ NONPAGED_AREA

If this is the first time you've seen this stop error screen, restart computer. If this screen appears again follows these steps:

Check to make sure any new hardware or SOFTWARE is properly installed. 
If this is a new installation, ask your hardware or software manufacurer for any new windows updates you might need.
If problem continues, disable or remove any newly installed hardware or software. Disable BIOS memory options such as caching or shadowing. 
If you need to use safe mode to remove or disable components, restart your computer, press f8 to SELECT advanced startup options, and then select safe mode.

Technical information:
***STOP: 0x00000050 (0xE13D4000, 0x00000000, 0x8053B912, 0x00000001)

Beginning dump of physical memory
Physical memory dump complete.
Contact your system adminstator or technical support group for further assitance.