I bought a second hand 2018 Mac mini, went to do a clean install of Big Sur, wiped the drives as per instructions. The guy I bought it off neglected to tell me it was dual-boot macOS/Windows and now I can't boot from either Windows or the USB Big Sur installation thumb drive.
I've tried Internet Recovery but error 1008h indicates recovery didn’t start to load or let me erase things.
Is there like an
fdisk utility that I can sort this out or another way around this?