Hi! did you change jumpers or use different Operating system than it was before, normaly when you didn't configured hard drive properly, or BIOS Configuration or use different OS could also means change of hard drive space or just sometimes motherbord can't handle the hard drive size and the only solution to that is to set drive space to a low size.
PS. TELL US WAT DID YOU DO DIFFERENT THAN BEFORE, IT COULD BE SEVERAL REASONS