Could be anything, really. Borrow a RAM stick/hard drive from a friend. Try replacing yours with his to see if there's anything wrong with those two first.
Mac Reviewed by Mac on . desktop pc keeps restarting hey KWWH tech's i need help immediately .....my desktop pc is booting till window but before reaching desktop it restart and gives two option start windows normally for start up repair when clicked on windows normally same things happen and when clicked on repair its repairs successfully but same issuse safe mode--no go safe mode with networking --no go made bios default but still no go did my windows crashed or my hard drive gone bad Rating: 5