Posted 22 May 2010 - 12:32 AM
I couldn't find much info on STUB so had a look thru my machine using "Everything" and there are a number of entries, pointing to configuration files and Dlls.
A possible reason you can't delete some folders is that they could be Windows ones and it will not allow you to touch them. Windows makes many folders and leaves a lot of them empty for future use, but they are doing no harm and not taking up any appreciable space so I wouldn't worry about it.
Playing with Windows for no good reason could possibly cause you quite a bit of grief. Third party programs are only as good as their maker so I would tend to be a bit wary; read reviews from other users on CNET or similar before using. There are many excellent free programs out there, but there are also dogs so just be a bit careful.