In oups.com,
Mike Grant had this to say:

My reply is at the bottom of your sent message:

I booted up my computer this morning, after briefly going on to play a
game that has worked fine for the past month. Where i was greeted with
Operating System not found.

So i got my startup disk, and it told me that the fat orfat32 partion
may be corrupted, or i may have a virus and so forth.

So i rebooted, and went into the bios, the hard drive has disapeared.

I took the power out, checked the connections, nothing wrong at all.

So i rebooted, and as i don't trust microsoft, i tried to install
linux, this told me there was no hard-drive in my machine at all.

I'm at a loss what to do, any help please.

Some suggestions... Grab the drive out of the box and read it, find the
manufacturer of it, go to their site, grab their diagnostic tools, and check
the drive. That's what I'd do. Check the cables, if you have a spare ribbon
cable then toss it in there and see if that makes a difference. Check the
power, if you have a spare power plug in the case try using that one instead
of the one that you were using. Check the drive (just hook it up where the
CD/DVD would be and disable the optical drive for the time being) in the
computer that you're using right now and see if it's listed there either in
the BIOS and/or in the OS.

--
Galen - MS MVP - Windows (Shell/User & IE)
http://dts-l.org/

"A man should keep his little brain attic stocked with all the
furniture that he is likely to use, and the rest he can put away in the
lumber-room of his library where he can get it if he wants it."

Sherlock Holmes