Can't reboot after fail

I've experienced crashes a few times over the three years I've had my
current computer. I upgraded to Vista from XP about two years ago; and,
about a year ago had to reinstall and reformat the computer after a
system crash.

The error message I am getting now is similar to the one I got a year
ago when the system failed. However, this time, I simply cannot
interface with the computer. The screen brings up an "HP" logo with
directions to push "esc" "f10" etc, and if I put the boot disc in, I get
the message "Push 'f' to format or 'q' to quit."

Normally, I would be able to push 'q' and I'm good to go.

What is happening now is that I cannot communicate with the computer at
all. It doesn't recognize, record, or respond to any input.

I thought maybe my keyboard was broken, but cleaning and switching the
keyboard didn't help. I still cannot communicate with the computer to
get into the boot menu.

What is my next step? Am I at a loss, and the computer is kaput?
There is no major data on the hard drive, everything is backed up, but
my powerful desktop is not working, and I kind of need it to.

Thank you for any help you or advice you may have.


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acupps