Stuck in BIOS after changing to UEFI (unrevertable)

[drksen]

Hello,

As many have described, I went on to change my SSD from MBR to GPT and then switched to UEFI in my BIOS. However, now :
- When restarting in UEFI mode, my computer stays in BIOS.
- When restarting back in CSM, my computer does not find anything to boot from ("Reboot and select proper boot device").

So I'm finding myself stuck here. If that helps, motherboard is MSI Gaming Plus 450B, AMD processor, and I used some third party software for the disk conversion (diskgenius.com).

Thank you so much for anyone able to help !

 

[Trouble]

Not sure but I suspect that the conversion was a simple conversion and when you boot a
UEFI/GPT/SecureBoot machine it looks for and efi partition on the disk drive that contains the Windows Boot Manager or at least a pointer to it.

I suspect that was not created as part of the conversion process.
There are multiple sites with information as to how to reconstruct / rebuild / repair these problems, but they are not for the faint of heart, as they involve the command prompt, diskpart, bcdedit and other assorted utilities.

Windows 11/10 Boot Repair: Fix UEFI Boot Issue on Windows 11/10/8/7

This article provides effective methods and detailed guides for Windows 10 boot repair. If you are having problems with UEFI bootloader and fail to boot your Windows 10/8/7 system, follow the useful solutions to fix UEFI boot on Windows 10.

www.easeus.com

https://en.naneedigital.com/article/how_to_rebuild_boot_configuration_data_file_in_windows_10

Please do not purchase or otherwise employ any software products suggested in the links above (except of course the native utilities).
I only include them as reference material and do not in any way advocate for any third party software products.

Hopefully you built the recovery / rescue media from that software as you may find yourself using it to convert it back to mbr
and reverting back to legacy bios.

 

[drksen]

Thank you so much for taking the time to answer me.

I resorted in doing a full, clean installation of Windows 11 from USB. I deleted all partitions during the process and it's working well now, with the BIOS still in UEFI. (Ofc my data was backed up before the disk conversion.)

I reckoned that trying to revert back to MBR state would be an avoidable pain to inflict on oneself... And you certainly seem to confirm that!

 

[Trouble]

Sorry to hear, but....
I do love that fresh registry smell that comes with a custom clean install.
Glad you had the backup.
Thanks for the follow-up info, much appreciated.
All the best going forward.
Randy