MBR2GPT error 0x000036B7

Anthony Medina 0 Reputation points
2026-11-11T23:05:20.31+00:00

Trying to convert my main hard drive from Legacy to UEFI and I am getting the error: MBR2GPT error 0x000036B7

Windows for home | Windows 10 | Settings
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  1. Manoel Barros 23,460 Reputation points Independent Advisor
    2026-11-12T16:05:19.36+00:00

    Thanks for the details! In this case, you should try to carry out the procedure through WinRE, using the installation media (ESD-USB), without the /allowFullOS parameter.

    1. Turn off your computer >Go to your PC’s BIOS > Check if the boot order is correct.
    • When connecting the PC, press the F2 keys continuously until you reach the BIOS. Also try the DELETE/DEL, F10, F8, ESC or F4 keys.
    • Enter the advanced mode (F7 key) > Go to Boot option > Boot Order > Select "UEFI: <Install Media Mark>" option first.
    • If you have questions about which device you should select in First Place (#1), take pictures from the Boot tab and attach it to this topic.
    1. Save and Quit (Press F10 Key) > When you reach the Language Selection Screen and Keyboard Layout, click Next > On the Installation Screen, click "Repair Computer"
    2. In Recovery Mode, select Troubleshooting > Command Prompt > Run the sequence of commands below to confirm the correct disk:
    diskpart

list disk

select disk 0

detail disk

### When executing the command above, the volumes “SSD LOCAL DISK” and “SIMPLE” should appear. If they do not, change the 0 to a 1 in the previous command and run the command above again. The correct disk should display the aforementioned volumes. Make a note of the number of the correct disk.

exit
    1. Once you have the number of the correct disk, run the following commands in the command prompt again:
    ### Replace the 0 with the number of the correct disk, if it is not 0.

mbr2gpt /validate /disk:0
mbr2gpt /convert /disk:0
    1. If the conversion is successful, you must enter the BIOS > Change the boot mode to UEFI > Disable CSM/Legacy > Save and restart (usually F10 > Save and restart).

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  2. Anthony Medina 0 Reputation points
    2026-11-12T01:50:36.14+00:00

    mbr2gpt covert failure error screenshotmbr2gpt covert failure error.JPG

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  3. AI answer

    2026-11-12T01:37:59.12+00:00

    Run MBR2GPT offline from Windows Recovery Environment (WinRE) without /allowFullOS, because this allows it to reuse a suitable existing system partition instead of always shrinking the active Windows partition to create a new EFI System Partition (ESP).^1^

    Convert from WinRE

    Back up important files first. A successful conversion changes the disk layout, and the PC must subsequently boot in UEFI mode.

    1. Confirm that the computer’s firmware supports UEFI.
    2. Enter WinRE using Windows installation media and open Command Prompt. This is the accepted resolution in matching 0x000036B7 cases.^2^
    3. Identify the Windows system disk:
    diskpart
list disk
list volume
exit
    1. Substitute the correct disk number below—commonly 0, but do not assume—and validate it:
    mbr2gpt /validate /disk:0
    1. If validation completes successfully, perform the conversion:
    mbr2gpt /convert /disk:0

    Do not add /allowFullOS while running in WinRE. In full Windows, the existing MBR system partition is in use and cannot be repurposed, so MBR2GPT must shrink the OS partition and create a new ESP. Offline, it can reuse the existing system partition when that partition is suitable.^1^

    1. Only after the command reports Conversion completed successfully, restart into firmware settings and change the boot mode from Legacy/CSM to UEFI. Microsoft’s checklist also specifies disabling CSM; verify the result afterward by opening msinfo32 and checking that BIOS Mode reports UEFI.^3^

    If conversion still reports 0x000036B7

    This error occurs while MBR2GPT is trying to create the EFI System Partition. Inspect the detailed logs rather than deleting or resizing partitions blindly. In WinRE/Windows PE, the default logs are under %windir%:

    type %windir%\setuperr.log
notepad %windir%\setupact.log

    The relevant files are setupact.log, setuperr.log, diagerr.xml, and diagwrn.xml; setupact.log and setuperr.log contain the most detailed disk-layout and conversion information.^1^

    Check the last MBR2GPT entries for which condition failed:

    • Partition count/layout: MBR2GPT requires no more than three primary MBR partitions and does not accept extended or logical partitions.
    • System partition: One partition must be active and recognized as the system partition, with a valid default Windows entry in its BCD store.
    • Disk-edge space: The disk needs space outside its partitions for GPT metadata.
    • ESP creation: If the existing system partition cannot be reused, MBR2GPT must shrink the Windows partition to create a 100 MB FAT32 ESP, or 260 MB on a 4K-sector disk.
    • Encryption: If BitLocker is enabled, suspend protection before conversion.

    These are documented conversion prerequisites and ESP-creation rules.^1^

    Do not delete a Recovery or System Reserved partition solely to make room. First identify the exact failed condition from setupact.log and capture the current layout:

    diskpart
list disk
select disk 0
list partition
list volume
exit

    If the log reports a format or disk I/O failure rather than an inability to shrink or reuse a partition, check the disk’s health before another conversion attempt; a matching Microsoft Q&A case notes that a format failure can indicate a bad disk.^2^

    References

    1. MBR2GPT.EXE
    2. Cannot create EFI system partition. Error: 0x000036B7 when running mbr2gpt.exe - Microsoft Q&A
    3. MBR2GPT tool test guidance
    AI-generated content may be incorrect. Read our transparency notes for more information.

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  4. Manoel Barros 23,460 Reputation points Independent Advisor
    2026-11-12T00:45:41.3966667+00:00

    Hi!

    This error usually appears alongside the message “Cannot create EFI system partition.” Did this message appear along with the error?

    I need more details about your situation—specifically, what you have already tried and the environment in which you performed these actions. To help me get a clearer picture, please answer all of the following questions:

    1. Are you running the MBR2GPT command from within Windows, or from the Recovery Environment / a USB flash drive?
    2. What exact command are you entering? Please provide the full commands and the sequence of steps you followed.
    3. Which disk are you attempting to convert? For example, is it the system disk, a secondary disk, an external disk, etc.?

    It is worth noting that if the disk has a defect—which has been the case in several other discussions—MBR2GPT will fail. However, before concluding that this is the cause, there are a number of tests you can perform.

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