M
disk boot failure
Moderate
Microsoft · Windows
The BIOS found a boot device but failed to read a valid operating system from it — the boot sector or boot files on the disk are damaged or missing
Quick Answer
Error code Disk Boot Failure on your Microsoft Windows means: The BIOS found a boot device but failed to read a valid operating system from it — the boot sector or boot files on the disk are damaged or missing. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
21H222H223H2Server 2019Server 2022
Likely Causes
  1. Corrupted Master Boot Record (MBR) or GUID Partition Table (GPT)
  2. Boot sector virus or malware that overwrote the boot files
  3. Failed Windows update that corrupted boot manager files
  4. Hard drive with developing bad sectors in the boot region
How to Fix It
1
Boot from a Windows installation USB drive (create one at microsoft.com/software-download)
2
Select 'Repair your computer' > Troubleshoot > Command Prompt
3
Run: bootrec /fixmbr to repair the Master Boot Record
4
Run: bootrec /fixboot to write a new boot sector
5
Run: bootrec /rebuildbcd to rebuild the Boot Configuration Data
6
If the above fails, try: bcdboot C:\Windows /s C: /f ALL (adjust drive letter if needed)
7
Run: chkdsk C: /f /r to check for and repair disk errors
8
If none of these work, the boot region of the disk may be physically damaged — back up data using a Linux live USB and reinstall Windows
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
Windows installation USB drive
Replacement drive if disk is physically failing
Related Error Codes
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