I tried all of the proprosed solutions:
1. Uninstalling Anti-virus (no joy.)
2. Chkdsk c: /f /r (no joy.)
3. Removing recently installed programs. Removed (3) recently installed programs before coming to the conclusion that this is not working.
4. Safe mode boot / system restore. (no joy.)
Solution: Run the hard drive as the second drive on another windows 7 system. Run scandisk (check both boxes.) Let it run.
Move the drive back to the original system and bang!! it works!!!
Had to reinstall some programs but beats reinstalling everything or re-imaging.
Hope this helps somebody get through this non-sense.
Ad_Don