mazazomazazo
New member
- Joined
- Sep 1, 2026
- Messages
- 4
Motherboard: MSI B850 Gaming Plus WiFi
BIOS: Updated to the latest version via M-Flash (issue persists on latest BIOS)
Storage: Single NVMe/SATA SSD, GPT partition table, Windows installed in UEFI mode
Issue description:
I am trying to enable Secure Boot, which requires disabling CSM / switching to UEFI-only boot mode. However, every time I change the "BIOS UEFI/CSM Mode" setting from CSM to UEFI and save, the setting reverts back to CSM on its own the next time I enter the BIOS. This happens consistently and prevents me from enabling Secure Boot at all.
Steps I have already tried, none of which resolved the issue:
1. Updated the motherboard BIOS to the latest available version using M-Flash from a FAT32 USB drive.
2. Performed "Load Setup Defaults" after the BIOS update, then manually changed only the "BIOS UEFI/CSM Mode" setting from CSM to UEFI without touching any other setting in the same session, then saved and exited.
3. Allowed the system to fully boot into Windows after the change before re-entering the BIOS to check the setting.
4. Verified there is only a single storage drive connected (no secondary drives, USB drives, or optical drives attached) at the time of the change.
5. The SSD is confirmed to be using a GPT partition table, and Windows was originally installed in UEFI mode (not Legacy/MBR).
Despite all the above, the BIOS UEFI/CSM Mode setting still automatically reverts to CSM after a save/reboot cycle.
Request:
Could you please confirm if this is a known issue with the current BIOS version for this board, and whether there is a fix, a specific beta BIOS, or a required setting sequence to make the UEFI mode change persist?
Thank you.
BIOS: Updated to the latest version via M-Flash (issue persists on latest BIOS)
Storage: Single NVMe/SATA SSD, GPT partition table, Windows installed in UEFI mode
Issue description:
I am trying to enable Secure Boot, which requires disabling CSM / switching to UEFI-only boot mode. However, every time I change the "BIOS UEFI/CSM Mode" setting from CSM to UEFI and save, the setting reverts back to CSM on its own the next time I enter the BIOS. This happens consistently and prevents me from enabling Secure Boot at all.
Steps I have already tried, none of which resolved the issue:
1. Updated the motherboard BIOS to the latest available version using M-Flash from a FAT32 USB drive.
2. Performed "Load Setup Defaults" after the BIOS update, then manually changed only the "BIOS UEFI/CSM Mode" setting from CSM to UEFI without touching any other setting in the same session, then saved and exited.
3. Allowed the system to fully boot into Windows after the change before re-entering the BIOS to check the setting.
4. Verified there is only a single storage drive connected (no secondary drives, USB drives, or optical drives attached) at the time of the change.
5. The SSD is confirmed to be using a GPT partition table, and Windows was originally installed in UEFI mode (not Legacy/MBR).
Despite all the above, the BIOS UEFI/CSM Mode setting still automatically reverts to CSM after a save/reboot cycle.
Request:
Could you please confirm if this is a known issue with the current BIOS version for this board, and whether there is a fix, a specific beta BIOS, or a required setting sequence to make the UEFI mode change persist?
Thank you.