Well, it looks like either:
Y
- our USB boot disk doesn’t have a system partition on it (in other words, it doesn’t have an operating system to boot to)
- Your USB boot disk has a disk error (The USB disk might be broken or the system partition has been corrupted)
- You may have the boot order set incorrectly – perhaps it’s trying to boot to the hard drive that doesn’t have a system partition on it, instead of booting to the USB disk
To fix the non-system-disk-or-disk-error, check that the PC is set to boot from USB (BIOS settings). Failing that, try recreating your USB boot disk.