Possible reasons why you received the error message "Another user on this device uses this Microsoft account, so you can't add it here".
1) You added Microsoft Account through Email & app accounts or through signing in OneDrive App etc
What you need
- Internet Connection
- A Microsoft Account
- Windows 10 operating system
Instruction: (Remove Microsoft Account through “lusrmgr.msc”. ) AKA“Advanced user management”
1) Run “lusrmgr.msc” through Run or Start Menu
2) Navigate to Users and Delete the Microsoft Account that are causing the issues. (Please do take note that information regarding the Microsoft Account will be deleted). Warning: Do not delete the wrong account.
3) Sign in with Microsoft Account again under ("Start> Settings> Accounts> Your Info> Sign in with a Microsoft account instead")
4) Done.
** I solved my Microsoft Sign in Issue using this solution above, this solution will replace your local account with Microsoft account. But you can always revert back if you want.
I hope this post will be helpful.
Hope everyone enjoy the post.