I have renamed bunches of files by dumping the file list to my Braille Lite from DOS using the dir *.* >com1 command. This supposes that you have the port and the Braille Lite set with the same parameters. You have the Serial port turned on, and you have a file large enough to take the data. I have then added REN and a space to the beginning of each line, and used a variety of methods to add a space and the new file name at the end of the line. I have then renamed the file with a .bat extension and sent it back to the PC for execution. I would make a backup copy of the original files in case of errors in the batch file.