Getting a error when booting up Windows

Hi all, I was unware what part of the Avast forum to post it , so I’d though I would post it here.

Anyway I like to run Hitman Pro scans every so often, but time upon running one it caused my computer to crash.

When I rebooted it, I get greeted by a message saying
"NTLDR is Missing, Press Ctrl + Alt + Delete to restart

I am able to get on computer. by pressing F8 before it gets there and select what slave drive I want to boot up it from.

Could anybody help me?

It has deleted system critical files. There is an MS resolution here http://support.microsoft.com/kb/318728

Just wondering could I create a system restore point and would that reverse the effetct?

Probably not as restore cannot be accessed from another drive

Thanks anyway but I’ve fixed it ;D