have u made any progress? the usb slot is a old problem. disregard if you are using up to date emus. folder not found is the normal error at emulator startup when changing directories. usb not found is another avenue. one i have not encountered running everything on FAT format. Some info would be useful on your side to help with your problem. Are you using Fat Partition? HDD size & make? Emulators up to date, versions. Ill help out as much as possible.