Hi, for people want just copy / past ROMS/BIOS directly on their MicroSD under Windows like a USB Key, just read this tips:
1/ For Install latest batocera build on your MicroSD:
Download & install on your computer 'MiniTool Partition Wizard 10", it's a free software, you can download for free here :
Use a MicroSD > USB 2.0/3.0 Adaptator or your Card Reader, insert your MicroSD and run MiniTool Partition Wizard 10
On your MicroSD Delete all partitions and create a Primary Partition FAT32, apply changes
2/ For Flash Batocera Build on your MicroSD:
3/ First Boot on your RPI3 or Other
After first boot, close Batocera
4/ Plug Again your MicroSD on your Computer
Return in MiniTool Partition Manager and format secondary partition "Others" in FAT32
5/ Return in your RPI3 or Other & boot with the MicroSD and change settings storage to internal and shutdown batocera from menu
6/ Finally plug your MicroSD on your computer and now your Share partition is available with all Batocera folders, all folders has been created and you can directly transfert your Bios, Roms & more...
7/ ... When it's done you can plug your MicroSD on your RPI3 or other and enjoy your games!