MBR2GPT - Unable to activate Secure Boot in BIOS

Question

MBR2GPT - Unable to activate Secure Boot in BIOS

Deepak166 20

(DHi, i recently changed my boot drive ssd from 256gb to 1tb, i previously managed to activate on my previous drive thanks to the help of someone here.

My disk was MBR so i used cmd to convert it to GPT, everything went fine but at the end of its process it said this:

mbr2gpt: Call WinReReapir to repair WinRE
MBR2GPT: Failed to update ReAgent.xml, please try to manually disable and enable Win

After this i went into BIOS but still no option to enable secureboot. I am currently in Windows UEFI mode and CSM is enabled. In the secureboot tab it said and still says:

Secure boot status: User (this is Greyed out)
Platform Key (PK) State: Loaded (This is greyed out)
OS Type: Windows UEFI Mode (Dropdown menu available with "Other OS" Option)
Key Management (leads to different tab)

CSM Tab:

Launch CSM: Enabled
Boot Device Control: UEFI and Legacy OPROM
Boot from Network Devices: Legacy Only
Boot from Storage Devices: Legacy Only
Boot from PCI-E Expansion Devices: Legacy Only
User's image

(Disk 1 is the drive in question)

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Answer 1

Ivan B 124.1K Independent Advisor

Hi,

This is because CSM is enabled and Secure Boot won't load the keys.

Search for msinfo32.exe in the search bar, take a screenshot, and post it here so we can see the correct laptop model or desktop configuration.

First, access the BIOS, go to the boot tab, and see if the SSD is being recognized as Windows Boot Manager or UEFI: and the SSD model.

You have to change all of this to UEFI after disabling CSM.

Boot Device Control: UEFI change to UEFI only. Boot from Network Devices: Legacy Only change to UEFI. Boot from Storage Devices: Legacy Only change to UEFI only. Boot from PCI-E Expansion Devices: here for legacy and UEFI if the option is available.

If so, you must disable CSM, save the BIOS, access the BIOS again, check if the boot, UEFI, or Windows Boot Manager is being recognized, and save the boot in Windows.

After it boots into Windows, restart and access the BIOS again and see if the Secure Boot option is enabled, save it, and boot into Windows.

Then access msinfo32.exe, take a screenshot, and post it here.

Thanks

Deepak166 20 Reputation points

2026-06-24T22:40:01.4033333+00:00

this is before doing what you have mentioned above.
Ivan B 124.1K Reputation points Independent Advisor

2026-06-24T22:45:44.8166667+00:00

Hi,

Secure boot is now enabled.

If so, did you deactivate CSM?

Thanks
Deepak166 20 Reputation points

2026-06-24T22:48:10.5233333+00:00

no, i just turned CSM off in bios and restarted now. should i turn it back on?
Ivan B 124.1K Reputation points Independent Advisor

2026-06-24T22:50:28.65+00:00

Hi,

Do not turn it on again; keep CSM disabled and follow the process exactly as I described in my first reply.

Thanks.
Deepak166 20 Reputation points

2026-06-24T23:00:45.49+00:00

Hi, prior to turning CSM off in bios i had 2 boot priorities, Boot Option 1: Windows Boot Manager (Samsung SSD 990 EVO), Boot Option 2: Samsung SSD 990 EVO. After turning CSM off i now have just Boot Option 1: Windows Boot Manager (Samsung SSD 990 EVO).

All the options you mentioned were all in the CSM tab, after disabling CSM these options are gone and i am only left with Launch CSM: Disabled. So i am unable to change everything to UEFI from Legacy like you asked, unless its somewhere else?

In the secure boot tab everything is the same as it was: Secure Boot Status: User, Platform Key (PK) state: Loaded, OS Type: windows UEFI
Ivan B 124.1K Reputation points Independent Advisor

2026-06-24T23:03:32.87+00:00

Hi,

In this case, it's correct. If it disappeared, you save the BIOS, access Secure Boot, and see if it's enabled.

If you have it as a user, everything is fine, provided the keys loaded.

Now try starting Windows. If it starts correctly, it's working, and msinfo32.exe must have Secure Boot set to ON.

Please consider rating the question (accept the answer or not), or Access the community at Microsoft Q&A if you have further questions.

Thanks