When you tried turning your system back on, did a message
in white lettering on a black screen come up that it
was "unable to recognize Drive C:" (or whatever the name
of your hard drive is)? If so, then it is probably a hard
drive failure, sorry to say it. Also, has it gone to
the "Dell/Gateway/HP/ or whatever screen and then the
screen is black and no messages come up or anything? If
so, then you probably had the same problem I did before
with my BIOS. It would be best to either bring it into
service or try writing zeros to your hard drive by putting
in your Drivers CD or Restoration CD, when it starts up
click "Boot from CD," then go into the Command Prompt, and
then when it says the drive, type GWSCAN to go into the
scan for your hard drive, and you can do a full scan on
your hard drive to see if any problems occur (PLEASE NOTE:
this may take an hour or two), and if it says "too many
errors have occurred, then you can go back to the GWSCAN
screen and write zeros to the hard drive, which be warned,
WILL DELETE EVERYTHING! You can then restart your system
over again. If, when running the "Full test," it says it
failed, then the hard drive probably failed on you. Good
luck on resolving your issues!
~Crystal~