Non System Disk Or Disk Error USB Boot Posted on by McLovin IT Support Forum › Forums › Windows › Windows 7 › Troubleshooting › Non System Disk Or Disk Error USB Boot Tagged: Bootable USB This topic contains 1 reply, has 2 voices, and was last updated by Webmaster 4 years, 9 months ago. Author Posts July 17, 2014 at 8:42 am #475 McLovinParticipant When trying to boot from a USB disk, I get: Non system disk or disk error What does a non system disk or boor error mean? July 17, 2014 at 8:49 am #476 WebmasterKeymaster 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. Author Posts You must be logged in to reply to this topic.