CMOS Checksum Error Envy 360

[MB_1980]

I replaced my laptop battery when it would no longer hold a charge.  The new battery charges fine, and the computer worked well with it for a few days.  Then I started getting the CMOS Checksum error 502 message - and the laptop won't work unless plugged in.  Other Community posts have stated that my Envy 360 does not have a motherboard CMOS battery, so the recommended fix for this problem is to download a new BIOS.  When I go onto the HP Support page it tells me that my laptop should have the Windows 10 operating system; it has Windows 11 (I undoubtedly updated it when Microsoft made Windows 11 available).  So I can't get to a BIOS update for Windows 11.  

What's the recommended solution?  Do I say I have Windows 10 and then download a new BIOS?  Or is there a BIOS available for this machine to run Windows 11...and I just have to have a different way to access that BIOS?

[Max3Aj]

@MB_1980, Welcome to HP Support Community. 

Thank you for posting your query, I will be glad to help you. 
Upon system startup, a BIOS checksum test is conducted. If the test fails, indicating a potentially corrupted BIOS, the system automatically replaces it with a backup copy and continues the boot process. A message will appear for 15 seconds before an automatic reboot, but you can press Enter to skip the delay.

To resolve the CMOS Reset Error (502), restore the BIOS.

1. Press enter to restart the PC.
2. If the error displays after restarting, try to restore the BIOS using a USB drive. 

You may refer to this document to restore BIOS -  HP Notebook PCs - Recovering the BIOS (Basic Input Output System).
 

I hope this helps. 

Take care and have a good day. 

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Max3Aj

HP Support