[Solved] 0xc000000f winload.efi: BCD device/osdevice pointed to wrong partition

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[Solved] 0xc000000f winload.efi: BCD device/osdevice pointed to wrong partition

chenqiqi777 20

I am sharing a Windows 11 boot failure that I recovered from because it may help others troubleshooting error 0xc000000f and winload.efi. System - Windows 11 Pro Insider Preview 26H2, build 26300.8935 - UEFI/GPT - Two physical SSDs - More than one EFI System Partition and Windows Boot Manager entry The problem followed very slow boot, a black screen with a cursor, failed Automatic Repair, SFC corruption, and DISM error 0x800f0915. The machine eventually stopped at: \WINDOWS\system32\winload.efi 0xc000000f In WinRE, I verified: - C:\Windows\System32\winload.efi existed - C:\Windows\System32\ntoskrnl.exe existed - D:\Windows\System32\winload.efi did not exist - D:\Windows\System32\ntoskrnl.exe did not exist The active Windows Boot Loader entry nevertheless showed: device partition=D: osdevice partition=D: path \WINDOWS\system32\winload.efi The actual Windows installation was on C:. I exported the BCD first, then corrected both values: bcdedit /export C:\BCD-backup bcdedit /set {default} device partition=C: bcdedit /set {default} osdevice partition=C: The 0xc000000f / winload.efi error disappeared. Later, a Windows installation or repair attempt entered a reboot loop. The UEFI F12 menu showed two Windows Boot Manager entries. Selecting the second entry allowed Setup to detect the incomplete installation, roll it back, and return to the original Windows installation. Important: Do not blindly reuse these commands. WinRE drive letters can differ. Verify the actual offline Windows volume and back up the applicable BCD store before editing it. I cannot determine whether Windows Setup itself caused the mismatch. Possible factors include the failed installation or rollback, multiple EFI partitions, firmware boot selection, and earlier recovery work. Confirmed facts: - The active BCD entry pointed to D: - The actual Windows installation and loader were on C: - Correcting both device and osdevice removed the boot error Has anyone else observed this on a multi-EFI Windows Insider system?

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Answer 1

Yes. The documented cause matches that pattern: 0xc000000f can occur when the BCD is corrupted or when the DEVICE and OSDEVICE references in the boot configuration are missing, unknown, or point to the wrong partition.

For a UEFI system, the supported checks are:

Start in WinRE and run bcdedit.
In Windows Boot Manager ({bootmgr}), verify device and path point to the correct boot partition and boot loader.
In Windows Boot Loader ({default}), verify device, osdevice, path, and systemroot point to the actual Windows partition and loader.
If entries are wrong, back up the BCD first:
```
   bcdedit /export C:\temp\bcdbackup
```
Then correct the values with bcdedit /set {identifier} option value.

For UEFI Windows boot loader entries, the expected values are typically:

bcdedit /set {default} device partition=C:
bcdedit /set {default} osdevice partition=C:
bcdedit /set {default} path \windows\system32\winload.efi

If the BCD store is missing or badly damaged, bootrec /rebuildbcd is the documented rebuild step.

On systems with multiple EFI partitions or multiple boot entries, the key point is to verify the active BCD store and the actual offline Windows volume before changing anything. WinRE drive letters can differ from normal boot, so confirming where the Windows folder and winload.efi actually exist is required before editing device and osdevice.

If the scenario is an Azure Generation 2 VM, the same principle applies, but the BCD store is typically accessed through the EFI partition path:

bcdedit /store <Boot partition>:\EFI\Microsoft\Boot\BCD

Risk note: editing BCD settings can make the system unbootable if the wrong store or partition is used. Export the BCD first before changing device, osdevice, or path.

References: