Pick Which Systems To Display In Menu
In order to correct this you will need to navigate to ROMS folder to add or delete games.
\batocera\share\roms

Add ROMs From USB To Hard Drive
You can remote into the share on your network by host-name or IP address on address bar, http:\\192.0.0.0 or host-name. For big games you can copy them to USB flash drive in batches or take disk out of game machine and connect to USB hard drive enclosure on your main computer and use a program like Linux File Systems for Windows by Paragon Software to access the EXT4 hard drive with out corruption.
"Batocera Linux Installation Tips, Tricks & Troubleshooting"