Renamer, Rename files is an advanced

Wonderful tool to rename files in bulk is that folders (only to rename folders and files without touching, click on Filter Settings when you click on Add Folders).
Through Renamer you can add a prefix beginning of the name, a suffix at the end, change the extension, remove a part of the name, substitute the name or part of it, go to uppercase to lowercase or vice versa (including the possibility of change case of letters only the first letter) and more. And also possible to combine all these rules together.
The program is very nice, better than competing programs, as currently only in English.
Operation is quite simple, although not as rivals (Lupas Rename is immediate).
Renamer allows you to perform more complex operations of others (as mentioned before, you may combine their many rules at once), but needs a bit longer to be understood. Fortunately there is a preview, so you can see in advance the changes to the various names.
Renamer is also available in portable, requiring no installation
Valuable program (which as mentioned can also rename the folders, not just the files in them), although my personal preference is still to Lupas Rename.

Renamer