Place the convert_xls_to_xlsx.py script in the folder of your choice. Place all .xls formatted Excel files in the same folder as the script that you want to convert to .xlsx Run the convert_xls_toxlsx ...
just run MP4toWEBM.bat in the same directory as all of the MP4 files you wish to convert. The script will convert all videos to WEBM format and leave them in the same directory, and move all old *.mp4 ...