BIOS Update for my PC not available on HP site for Windows 11

[plco43]

Hi All,

I have an HP Pavilion 690-0040NA PC that I bought new in December 2019.  The machine originally came with Windows 10 Home installed. I successfully upgraded to Windows 11 in 2022.  Prior to that upgrade I installed the latest BIOS version, that's AMI F.48, 27th July 2022.  The upgrade to Windows 11 was not offered by HP, albeit repeated testing using the Microsoft tool said that the PC was compatible with it.  This upgrade went without a hitch.

Approximately 3 to 4 weeks ago, after a Windows update, a few strange things started to happen.  I have been in the habit of shutting down the PC every evening, and switching off the power at the mains socket after it had shutdown. Now, when I switch on the mains socket, the machine starts to boot up on it's own without me touching the on button. It then shows a BIOS message as follows:

The CMOS checksum is invalid. The CMOS will reset to the default configeration, and the computer will restart.  Afterwards, please check the BIOS setup options to see if they change.

CMOS reset (502)

Enter - Restart the computer.

When this is on the screen, if I wait 30 seconds or so, or press Enter, the computer restarts and Windows 11 appears to boot normally.

I understand that Error 502 indicates that a BIOS update is required.  I have been on the relative page on the HP support site for my machine and found that one BIOS update is available, dated September 2023, but that only Windows 10 is selectable, there is NO option for Windows 11.

Can anyone please advise me how to successfully update the BIOS on my PC? Is the September 2023 BIOS update for Windows 10 offered by HP for my PC compatible with Windows 11?  My PC appears to have been running normally on Windows 11 for the past 2 years until this last Windows update approx 3 weeks ago.

Thanks

[resistencia]

Hi @plco43 

Error 502 also indicates that the RCT battery is damaged and needs to be replaced, this battery allows the changes made in the BIOS to be maintained even if the PC shuts down, if the battery fails the BIOS settings are constantly lost,

About the BIOS update, this can come by Windows Update, if you do not have it you can use the windows 10 version in windows 11, usually works without problems.

[plco43]

That's brilliant! Thanks very much, I didn't think about the battery.  The PC's 5 years old so the battery could be down on voltage.  I'll change it anyway then check Windows update.

Thanks for your help

[resistencia · Accepted solution]

You're welcome. Happy to help.

[plco43]

Replaced battery. Bit difficult as it was half hidden underneath the fat video card but got there in the end. Was going to do BIOS reset, but as soon as I turned the power on at the socket, the computer powered itself up and came up with the same BIOS message, then rebooted and Windows came up. So I restarted again, and tried to do a BIOS reset as per the HP advice.  Don't know if it worked, but still getting the same message again when I switched off and rebooted.  So went into BIOS settings, checked all settings, didn't change anything, pressed set default and save, rebooted and now all good, so solved.

Thanks for your help

[resistencia]

This happened because the CMOS battery is damaged, you lose all BIOS settings so you must load the BIOS defaults.

You're welcome, happy to help