File names do not usually cause problems, except perhaps when dealing with photos or audio files. In addition to the ID3 or EXIF tags, depending on the case, the other issue to be addressed carefully is what the file names.
Renamer is what you need to rename mass large numbers of files, no matter how many. To achieve this , Renamer offers several proven such as search and replace, insert or overwrite text, numbering files or just convert between lowercase and uppercase methods.
Renamer offers a fresh and user friendly interface, without turbid or exotic features panels, just a few text fields and a drop down box from which you select options Renamer offers.