Chuck has a good answer, get into the Bios, as he mentioned, and set the machine back to it's default config. You may also be able to run diags in the setup or you'll just see the error possibly. Seeing that you are not a computer expert, the next steps are a little trickier, but everyone has a friend with a stable level of competence (just make sure they really do). The Bios battery (again as chuck mentioned) is a cheap battery you can get anywhere (in most cases) and just pops out for replacement. The other possibility is the CPU came loose and needs to be seated better (ask your "friend"). It could be a host of other things, but too techy for this (or your computer could just be shot). As long as the hard disk is OK, your "friend" should be able to assist in data recovery.