I’m trying to run batocera on my nettop, via SD card or USB flash drive. But every time I get “an operating system wasn’t found” error. On the other computers everything runs fine with the same card, but only on the nettop error. Can you please tell me what may be causing it? The bootable usb flash drive is working fine.
Probably something regarding the boot order/priority in your BIOS settings.
Also you may have to disable secure boot.
Is your USB device viewable in BIOS ?
Can you force manually the BIOS to boot on a specific device ?