This is a page from the Flash Renamer user manual.

Keyboard Shortcuts

In order to use Flash Renamer the most efficient way you should learn the hotkeys for commands that you use regularly:

Windows Tip:
    In Windows, the interface control that has focus recieves input from the keyboard. In order to know which control that currently has the focus, a dotted rectangle is displayed around it. This visual confirmation makes it easier to work with the keyboard, such as when using the Tab key to navigate inside the application.

    But in Windows XP and above, this feature has been deliberately hidden by Microsoft. If you use the keyboard a lot, then it is wise to enable this feature again. Go to the Control Panel and open Display Properties. Here find the Appearance tab and click on the Effects button. Now uncheck the option called Hide underlined letters for keyboard navigation until I press the Alt key. (The location of this option might be different in Vista). This works not only for Flash Renamer, but for all applications that are built to work on XP and above.