This is the main window of Batch FileName Editor where you can choosea folder and start changing the filenames. 

Batch FileName Editor offers you the possibility to insert new strings in the names and you can specify the position. 

Batch FileName Editor allows you to change the extension display by modifying a part or its letter case. 

The Options window is the place where you can choose to display results after renaming or to integrate the application with the context menu of Windows Exploer. 

The Rename tab enables you to adjust the number of preview files and to exclude 'a, and, of' when capitalizing words.