Replace Text
If checked, the text you type in the first field will be replaced with the text you type in the second, for any files whose names contain that text. This is applied only to the name, not the path or extension. The text of the first field is not case sensitive. If you typed file in the first field and Frog in the second, a file in the list named My File.doc would be renamed to My Frog.doc.

Prefix With
If checked, any text you type in this field is inserted at the beginning of the filename. If you typed "Not " in this field, a file named My File.doc would become Not My File.doc.

Suffix With
If checked, any text you type in this field is inserted at the end of the filename. If you typed name, a file named My File.doc would become My Filename.doc.

Change Extensions To
If checked, all the files in the list will be given the extension you type in this field. Type the new extension with or without a preceding dot. If you typed txt, a file named My File.doc would become My File.txt.

Change Case To
If checked, the case of all the filenames in the list will be changed to either upper or lower case (according to which radio-button is checked). If uppercase is checked, for instance, My File.doc would become MY FILE.doc. If the Include extensions box is checked, the same change of case will be applied to the file's extension.

Note: If you are only changing the case of the filename, it may be necessary to refresh the view of the folder in Windows to see the effect of the change.