Concerning reg cleaner programs, although it takes time to become familiar with it, when I have problems with hack-attacks, programs which won't fully uninstall, etc., I just load regedit.exe and perform a Find. I do Repeat Find, and delete every instance pertaining to the program.

Performing regedit, there have been times I noticed parts of trojans which were still in my computer over a year after I'd uninstalled them.

The disadvantage to regedit is, that technicians will forewarn you, that if you try to clean your registry manually, one single mistake can have dire consequences to the OS. So, you really have to understand computers to do it safely.