It sounds like a S.M.A.R.T warning which is a thing in the BIOS which checks hard disks and warns of potential problems. I don't know if theres any way of telling exactly what it sees as the problem.
If you know the make of the hard disk you could go to the hard disk manufacturers website and download diagnostic tools which might give you some insight.
Its a warning, I've seen it on a PC and 2 years later the hard drive is still working perfectly, on the other hand I saw it on one and the drive failed 3 weeks later. I don't think its 100% but its sensible not to ignore it just in case.