BIOS / UEFI Error Code
Systems & Devices
BIOS / UEFI
OPERATING SYSTEM NOT FOUND | No OS detected
Industry
Systems & Devices
Canonical
/systems/bios-uefi/error-codes/operating-system-not-found/
Last Updated
Feb 27, 2026
Summary
Firmware could not find a bootable operating system on the selected device.
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What This Code Means
This message appears when the firmware boot process cannot locate an OS loader on the chosen boot device. Causes include incorrect boot order, non-bootable media, missing partitions, or drive failure.
Where Users Usually See This Code
- Immediately after POST
- After drive replacement, cloning, or partitioning
Why This Code Appears
- Boot order points to an empty or non-bootable device
- Boot partition/loader is missing
- Drive is not detected or cannot be read
What Typically Happens Next
- System cannot boot until boot device or OS installation is corrected
What This Code Is Not
- It is not an application error
- It is not a networking issue
Troubleshooting Checklist
- □ Confirm the drive is detected in BIOS/UEFI
- □ Set the correct boot device and remove external boot media
- □ If the OS was recently moved/cloned, verify partitions and boot mode match
- □ Backup data before repair attempts
Notes And Edge Cases
Secure Boot settings can also prevent boot if the loader is unsigned or the mode is incorrect.
Related Codes
8 links
- NO BOOTABLE DEVICE CodeBoot device missing
- BOOTMGR IS MISSING CodeBoot loader missing
- BOOT FAILURE CodeInsert system disk
- NTLDR IS MISSING CodeLegacy boot loader missing
- REBOOT AND SELECT PROPER BOOT DEVICE CodeWrong boot device
- BOOT DEVICE NOT FOUND CodeBoot device unavailable
- INVALID PARTITION TABLE CodeBoot partition issue
- PRESS ANY KEY TO BOOT CodeBooting from external media
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