question

Hello,
Try the following:
Turn off Sleep Mode
Reset/Remove Login PIN
Convert Microsoft Account to Local Account
Detailed information here:
Fix – Windows Hello Error 0x801c0451 on Windows 10 PC
https://www.howtoedge.com/fix-windows-hello-error-0x801c0451-on-windows-10-pc/#:~:text=2.-,Reset%2FRemove%20PIN,Win%2BI%20and%20select%20Accounts.

Besides, in github, a user shares an experience:
Since this and the other GitHub issue are the only results for error 0x801c0541 when searching online, here's what fixed it for our set up. The users were registered with an Azure MFA server set up on-premises which was configured only to allow authentication through the mobile app. These users, however, were receiving text messages for MFA when attempting to set up Windows Hello for Business.

They had to register their mobile device in the Authenticator app, wait for the change to propagate, and then go to https://aka.ms/mfasetup and change their preferred method of verification to be notified through the mobile app. Once that change was made and they approved the mobile app they were able to get Windows Hello for Business to register the PIN.
https://github.com/MicrosoftDocs/windows-itpro-docs/issues/2941

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Hello,
The steps you mentioned haven't solved my issue - Windows Hello Error 0x801c0451 on Windows 10 PC.
I really want to avoid a Windows reinstallation, but it looks for now there is no other fix.
Nevertheless, I'm trying to figure out how or if you read my question details. Did you copy the howtoedge.com link from my question and pasted in your answer?
When you answer a question do you read only the title?

Hey guys,
We dealt with this a bunch in our environment. What we found is that some PC's were showing duplicate accounts under "Email & Accounts" in settings. So, for example, when loading up the settings app in Windows and going into the "Email & Accounts" section, you might see 2 listings for user account "John.Doe@domain.com". This appears to cause issues in Windows (and Office), including with Hello setup. Not sure why the duplicate account shows up, but the solution is to go to %LOCALAPPDATA%\Packages\Microsoft.AAD.BrokerPlugin_cw5n1h2txyewy\AC\TokenBroker and rename the "accounts" folder to "accounts.old" and reboot. The duplicate account will be gone after a reboot, and Hello should properly complete set up. We've also noticed this fixing several other issues, including Office 365 randomly showing "unlicensed product" for a user with an active E5 license. Whenever duplicate accounts show up, it eventually causes issues!
Hope that helps.

Bingo! simple and effective. Thank you! Yes, seems to have resolved some other issues on my PC.

This fixed it for me as well on one system that for some reason it listed the same account twice under email and accounts. Glad you found that, since I was not having any luck on Microsofts general support since that error isn't listed.

The only thing I can maybe think of was something weird happened with Azure AD Connect when it was implemented. It had been decided at one point to have their AD account, and M365 account be different, and when connect was implemented, the M365 account was changed to be the same as the AD account. That is the only thing I can think of.

The thing is though, it only happened with one account, a couple others that had the same AD/M365 setup, only had one entry.