A client of mine had finally got long-haul WIFI into their area. Before that they were on Satellite Internet with a very low and capped quota (4 GB/month). Consequently things like Java and Windows updates were manual. As they were in the middle of no-where then not too many site visits by me either.
I remote desk-topped into their machine and was doing updates for them. The Java was version 6 so I added version 7 and tried to uninstall version 6. It wouldn’t do this. The uninstaller dialog box referred to a different version from what it said was installed in the Control panel installed applications list and it didn’t remove the installed version anyway but just exited.
The fix I found was to download the most recent Java version 6 (update 39) and install that and then that updated the installed software list and flushed the problem. I then uninstalled that new version and it worked – Java 6 was gone.