Shoutbox

Try changing the hard drive if possible, but my guess would be yes it's a hard drive failure.

A more simple check being to find a bootable CD and see if you can boot to that and read the hard drive.

If it was only Disk Read Error then it may have been that the bootsector had become corrupt, however if it gets past it some of the time then it indicates a mechanical fault - it can read some data before dying.