Ensure you have a formatted blank USB that is no bigger than 16GB. Plug the USB into one of the front USB ports of your CommBox.
While in the whiteboard application push the save icon in the bottom left corner of the screen.
Name your whiteboard file and select the save your file as a PNG or PDF. You are able to select which pages to save and finally select save to USB flash disk.
Close the White Board App and remove your USB from the port.