If you’re looking for either a first aid or just a file and folder rename tool, don’t look any further. The name you need to look for is Métamorphose.
I tried a lot bunch of tools which failed on the job because encodings in the filenames.
And then there is this wxWidgets based free software that is just doing the job. Do you have anything in your filesystem that you are not able to rename? Any operation prevented by the encoding of file- or diretory- names? – Try Métamorphose.
Métamorphose: A File and Folder Renamer – http://file-folder-ren.sourceforge.net/