Activation is failing after CMOS battery replaced

[basswinding]

I Initially had two retail Windows 8 licenses. I upgraded one PC to Windows 10 a while back. However I couldn't upgrade my other Windows 8 PC due to its old CMOS battery.
A few days ago, I replaced the battery, and the upgrade process went smoothly. However, Windows now believes that I've altered hardware and doesn't activate automatically. Interestingly, I noticed new devices listed on my Microsoft account page.
When trying to troubleshoot the activation issue, I'm prompted to select a device from my Microsoft account, but I only see my other PC, which is already activated with Windows 10. Entering my product keys didn't resolve the issue either.
Although I reached out to support, I'm yet to receive a response.
Is there any other solution I can try? Also, I'm uncertain about the implications of removing a device (unlinking from account) from my Microsoft account.
Thank you in advance for any kind of help.

 

[Bighorn]

Can't say for sure but was the power removed/unplugged from the computer when changing the CMOS battery? If so, it reset the BIOS to default and may be an issue with the activation. Changing that CMOS battery is the only time I leave the computer plugged in but turned off so as to save the BIOS settings, the ones that the User can change. When changing other parts such as RAM and add-in cards it's best to remove power.