Do you have a real Windows CD, or restore CD's, or what?
What preceeded this? Do you have any data you need to back up?
First thing to do is to diagnose the hard drive with free diagnostics from the hard drive manufacturer's site. Is the drive completely internal? Is there a chance it could have become dislodged?
It's one of the CDs that came with my laptop, some XP thing for repairing or reinstillation.
My computer was fine, then I let my partner use it for about two months.
Upon recieving it back, it kept shutting off randomly, but it would be fine when I turned it back on.
Yesterday, it did the aforementioned turning off business, and then upon starting it back up, I got the Unmountable Boot Volume message.
I'd like to keep a lot of stuff on it, but if that's inevitable, I'll do anything I can to fix it.
I'm assuming it's internal? Like I said, I'm a complete moron when it comes to anything about computers. I apologise.