A technician is troubleshooting a desktop computer that displays the error 'Operating System Not Found' during startup. Upon inspecting the system, the technician notices a non-bootable USB flash drive connected to one of the external USB ports. Which of the following is the most likely cause of this boot error?
- The system BIOS/UEFI is attempting to boot from the non-bootable USB drive prior to the primary hard drive.Answer
- BThe Windows Boot Configuration Data (BCD) file was corrupted by the connected USB flash drive.
- CThe computer requires running bootrec /fixboot from the command prompt to reassign drive letters.
- DThe Windows Event Viewer MMC snap-in must be used to repair the damaged master boot record.
Answer
The system BIOS/UEFI is attempting to boot from the non-bootable USB drive prior to the primary hard drive.
If the BIOS/UEFI firmware is configured with removable storage devices listed ahead of the primary internal hard drive in the boot order, the computer attempts to boot from the connected USB drive. Because the USB drive lacks boot files, the motherboard outputs an error such as 'Operating System Not Found'. Removing the drive or updating the boot sequence resolves the issue.
Step-by-Step Solution
Key Concept
BIOS/UEFI Boot Order Configuration
Estimated Time:1m 0s