Asus X541UV Windows update KB5063060 deleting BootOrder EFI environment variable? bios fix
I had 3 people contact me in a week because Windows suddenly didn't boot:
As you can see, all 3 are ASUS computers, but I believe the common factor is the BIOS being American Megatrends (AMIBIOS/APTIO).
The first two recovered just fine after a restart, but the third one didn't and was brought to me. The model is F541UV (X541UV).
Setup allows to add a boot option manually and the operating system boots just fine from both bootx64.efi and bootmgr.efi. However, there is no way whatsoever to save the option(s): upon a reboot the machine goes straight to the setup and the boot list is empty.
Further investigation reveals that the BootOrder environment variable is missing, the issue is pointed out by both efibootmgr on Linux and EasyUEFI on Windows. The latter also mentions the BIOS should recover itself, but it didn't even after a CMOS reset.
The solution consists in rewriting the BIOS, which I'm attaching here along with the faulty one, but I believe this is a critical problem that shouldn't happen in the first place.
Faulty: ASUS_X541UV_GD25B64C.zip
Clean (no DMI, not required): ASUS_X541UV_309_Clean.zip
Update capsule from ASUS: X541UVAS309.zip
Unfortunately a programmer is required because the setup doesn't allow you to flash a version that is the same or older and the latest was already installed.
At least one user managed to add the missing environment variable using WinAPI's SetFirmwareEnvironmentVariable, but unfortunately I cannot verify that as the computer is already back to the owner because they needed it urgently.
In any case, I hope this is helpful and spreads awareness!
As you can see, all 3 are ASUS computers, but I believe the common factor is the BIOS being American Megatrends (AMIBIOS/APTIO).
The first two recovered just fine after a restart, but the third one didn't and was brought to me. The model is F541UV (X541UV).
Setup allows to add a boot option manually and the operating system boots just fine from both bootx64.efi and bootmgr.efi. However, there is no way whatsoever to save the option(s): upon a reboot the machine goes straight to the setup and the boot list is empty.
Further investigation reveals that the BootOrder environment variable is missing, the issue is pointed out by both efibootmgr on Linux and EasyUEFI on Windows. The latter also mentions the BIOS should recover itself, but it didn't even after a CMOS reset.
The solution consists in rewriting the BIOS, which I'm attaching here along with the faulty one, but I believe this is a critical problem that shouldn't happen in the first place.
Faulty: ASUS_X541UV_GD25B64C.zip
Clean (no DMI, not required): ASUS_X541UV_309_Clean.zip
Update capsule from ASUS: X541UVAS309.zip
Unfortunately a programmer is required because the setup doesn't allow you to flash a version that is the same or older and the latest was already installed.
At least one user managed to add the missing environment variable using WinAPI's SetFirmwareEnvironmentVariable, but unfortunately I cannot verify that as the computer is already back to the owner because they needed it urgently.
In any case, I hope this is helpful and spreads awareness!
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