[SOLVED] OS not booting after BIOS update ?

[atotalnoob2]

Hi,
I wanted to update my MSI B450m Pro-M2 to the latest bios release (this) to replace my CPU. I downloaded the update into a pendrive, booted BIOS, going to the M-Flash menu to boot the USB and waiting for the update to complete. After doing it, everything look fine but every time the pc booted it entered in BIOS mode and I wasn't able to boot my SSD, where the OS is installed, although it was detected in the BIOS.

The only way to fix it it was by reinstalling a previous BIOS release and reinstalling Windows on my SSD, because I was getting a message saying "Operating system not found".
Did I do anything wrong updating the BIOS the first time? Might be a bug for being the latest release in beta version? Should I try it again? I really don't want being messing around with the BIOS but I really want to upgrade my CPU.
Thanks.

 

[Koekieezz]

Hi,
I wanted to update my MSI B450m Pro-M2 to the latest bios release (this) to replace my CPU. I downloaded the update into a pendrive, booted BIOS, going to the M-Flash menu to boot the USB and waiting for the update to complete. After doing it, everything look fine but every time the pc booted it entered in BIOS mode and I wasn't able to boot my SSD, where the OS is installed, although it was detected in the BIOS.

The only way to fix it it was by reinstalling a previous BIOS release and reinstalling Windows on my SSD, because I was getting a message saying "Operating system not found".
Did I do anything wrong updating the BIOS the first time? Might be a bug for being the latest release in beta version? Should I try it again? I really don't want being messing around with the BIOS but I really want to upgrade my CPU.
Thanks.

tried to enable CSM? if enabling CSM works, then you installed your windows on a legacy mode, mbr-bios to be exact. recent bios forces the secure boot requirement for win 11, which means you have to go full UEFI.

 

[atotalnoob2]

tried to enable CSM? if enabling CSM works, then you installed your windows on a legacy mode, mbr-bios to be exact. recent bios forces the secure boot requirement for win 11, which means you have to go full UEFI.

I get the option to choose between UEFI and CSM in a menu called "Advanced Windows OS Configuration". What do I choose?

After updating the BIOS I can only select as boot option to enter BIOS setup and to boot an USB. I will try boot the USB with the Windows media creation tool and try to install the OS again.

 

[SkyNetRising]

Did I do anything wrong updating the BIOS the first time?

BIOS update causes BIOS settings reset.
You have to change boot related settings to previous values or system will not be able to boot.

Relevant settings are:

boot mode - UEFI or legacy (CSM),​

secure boot - enabled/disabled (only in UEFI mode),​

sata controller mode - AHCI, RAID, IDE.​