Unable to fix error 0xc0000017 on advanced startup due to missing EFI System Partition on Win 10 PC

Snow 40 Reputation points
2026-07-10T04:58:58.34+00:00

Hi,

I wanted to upgrade to Windows 11 but I needed to change my BIOS mode from legacy to UEFI. However when I went to advanced startup to follow the instructions on how to change it I got the 0xc0000017 error when I clicked on the command prompt. I basically had the same issue the user had from [this](https://learn.microsoft.com/en-us/answers/questions/2338992/having-trouble-fixing-error-0xc0000017-(advanced-s) post up to the most recent response which still didn't get resolved. I also want to point out that when I typed >bcdedit/delete {badmemory}, I didn't get an error but an access denied message which is below here. 

C:\windows\system32>bcdedit/enum all
Windows Boot Manager
--------------------
identifier              {bootmgr}
device                  partition=U:
description             Windows Boot Manager
locale                  en-US
inherit                 {globalsettings}
default                 {current}
resumeobject            {57615d88-34bd-11eb-b184-1803733bf2bc}
displayorder            {current}
toolsdisplayorder       {memdiag}
timeout                 30
Windows Boot Loader
-------------------
identifier              {current}
device                  partition=C:
path                    \windows\system32\winload.exe
description             Windows 10
locale                  en-US
inherit                 {bootloadersettings}
recoverysequence        {57615d8a-34bd-11eb-b184-1803733bf2bc}
displaymessageoverride  CommandPrompt
recoveryenabled         Yes
allowedinmemorysettings 0x15000075
osdevice                partition=C:
systemroot              \windows
resumeobject            {57615d88-34bd-11eb-b184-1803733bf2bc}
nx                      OptIn
bootmenupolicy          Standard
Windows Boot Loader
-------------------
identifier              {57615d8a-34bd-11eb-b184-1803733bf2bc}
device                  ramdisk=[C:]\Recovery\WindowsRE\Winre.wim,{57615d8b-34bd-11eb-b184-1803733bf2bc}
path                    \windows\system32\winload.exe
description             Windows Recovery Environment
locale                  en-us
inherit                 {bootloadersettings}
displaymessage          Recovery
osdevice                ramdisk=[C:]\Recovery\WindowsRE\Winre.wim,{57615d8b-34bd-11eb-b184-1803733bf2bc}
systemroot              \windows
nx                      OptIn
bootmenupolicy          Standard
winpe                   Yes
Resume from Hibernate
---------------------
identifier              {57615d88-34bd-11eb-b184-1803733bf2bc}
device                  partition=C:
path                    \windows\system32\winresume.exe
description             Windows Resume Application
locale                  en-US
inherit                 {resumeloadersettings}
recoverysequence        {57615d8a-34bd-11eb-b184-1803733bf2bc}
recoveryenabled         Yes
allowedinmemorysettings 0x15000075
filedevice              partition=C:
filepath                \hiberfil.sys
bootmenupolicy          Standard
debugoptionenabled      No
Windows Memory Tester
---------------------
identifier              {memdiag}
device                  partition=U:
path                    \boot\memtest.exe
description             Windows Memory Diagnostic
locale                  en-US
inherit                 {globalsettings}
badmemoryaccess         Yes
EMS Settings
------------
identifier              {emssettings}
bootems                 No
Debugger Settings
-----------------
identifier              {dbgsettings}
debugtype               Local
RAM Defects
-----------
identifier              {badmemory}
Global Settings
---------------
identifier              {globalsettings}
inherit                 {dbgsettings}
                        {emssettings}
Boot Loader Settings
--------------------
identifier              {bootloadersettings}
inherit                 {globalsettings}
                        {hypervisorsettings}
Hypervisor Settings
-------------------
identifier              {hypervisorsettings}
hypervisordebugtype     Serial
hypervisordebugport     1
hypervisorbaudrate      115200
Resume Loader Settings
----------------------
identifier              {resumeloadersettings}
inherit                 {globalsettings}
Device options
--------------
identifier              {57615d8b-34bd-11eb-b184-1803733bf2bc}
description             Windows Recovery
ramdisksdidevice        partition=C:
ramdisksdipath          \Recovery\WindowsRE\boot.sdi
C:\windows\system32>bcdedit/delete {badmemory}
This entry cannot be deleted unless the /f switch is specified on the command
line.  Run bcdedit /? for more information.
Access is denied.

Then I followed the rest of the instructions on the post then used the >list partition command, no EFI system partition was located on any of the disks. When I opened Disk Management there isn't a EFI located and I don't know what to do to get the EFI back. Screenshot (394).png

Windows for home | Windows 10 | Performance and system failures
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Answer accepted by question author
Volume Z 1,765 Reputation points Volunteer Moderator
2026-07-12T03:02:04.8+00:00

Maybe shrinking drive C by 1 MB would work, preferably in disk management? :)

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Answer accepted by question author
Ramesh 181.6K Reputation points Volunteer Moderator
2026-07-10T05:27:06.4466667+00:00
  1. Please run msinfo32.exe, and click System Summary. Resize the columns in the right pane to make the entries visible, and post a screenshot.
  2. Open Command Prompt admin and run this command:
mbr2gpt /validate /disk:2 /allowFullOS

Post the output.

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4 additional answers

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  1. Ramesh 181.6K Reputation points Volunteer Moderator
    2026-07-12T07:34:49.95+00:00

    Pc health check says I can upgrade, I followed the instructions to manually refresh security and updates but it still says doesn't meet minimum requirements.

    Yeah, thought so. That's why I suggested running that compatibility telemetry scheduled task.

    Please share your Farbar scan logs for analysis.

    • Download Farbar Recovery Scan Tool 64-bit FRST64.exe
    • If the OS language is not English, rename FRST64.exe to FRST64English.exe.
    • Run the program. Don't check or uncheck any options. Click "Scan".
    • Add the two logs, FRST.txt and Addition.txt, to a zip archive.
    • Share the zip file on OneDrive or GoFile.io, and post the link here.

    Note: If Microsoft Edge or Chrome mislabels the Farbar Scanner executable as PUA/malware, choose to keep it by tapping … in the bottom bar, choosing Keep, and then choosing Keep anyway in the dialog that appears. See this screenshot. It's a safe tool used in most antimalware forums.

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  2. Ramesh 181.6K Reputation points Volunteer Moderator
    2026-07-12T07:05:54.82+00:00

    I was able to log in back to windows

    Ok. Please follow the steps mentioned in this article.

    Check if a device meets Windows 11 system requirements after changing device hardware | Microsoft Support: https://support.microsoft.com/en-us/windows/experience/compatibility/check-if-a-device-meets-windows-11-system-requirements-after-changing-device-hardware

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  3. Ramesh 181.6K Reputation points Volunteer Moderator
    2026-07-12T05:31:01.81+00:00

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