MrMoonshine

Thanks Romanoff. That explains things.

I don't know, but I think it would be a good idea (especially since I believe the bad sectors are already marked by check disk). Otherwise the de-fragmenter will attempt to write to these sectors.

Yes, that is the exact issue I had. I had to do a complete check disk at boot-up to fix it.

I ran defraggler a few times, but it always spent a long, long time. I thought this may be normal so I let it run. I now understand that my hard drive has a corrupted sector, and I think Defraggler was treating it as a normal one. Allowing Defraggler to run like this very nearly caused me to have to re-install my operating system. Until this issue is addressed I simply can't allow myself to defraggle my hard drive. There have been a couple of releases since the version I was using. I don't suppose that the issue has been sorted?