Windows 10: Can't Add Device to Existing Microsoft Account

Had a new Win10 computer made for me and can't add it to MS account; says invalid Serial #. Is that because it was built for me and I'll never be able to add it to the account?

:)

 

Activity Reporting error non-existent device

Hi,



Thank you for writing to Microsoft Community Forums.



I understand that a non-existent device is showing in the activity reporting. As you have mentioned that you have removed the device from Manage device limits for all family accounts, I suggest you to try removing the device from the child account
and check if that helps. Please follow the steps mentioned below:

1. Login to
   https://login.live.com with the child account.
   
2. Click on Devices.
   
3. Click on show details for the device that is non-existing.
   
4. Click on More actions.
   
5. Click on Remove PC.
   
6. Click on I’m ready to remove this PC and click on
   Remove.
   

Hope it helps.



Please reply with the status of the issue, we will be glad to help you further.



Nikhar Khare

Microsoft Community - Moderator

 

Unknown devices on my Microsoft account

Hello Flemmingk,

Could these other devices be from friends that you may have signed in to your Microsoft account on for something?

Either way, you can remove these devices.

*Arrow Microsoft Account - Remove Devices User Accounts Tutorials

Afterwards to be safe, I would recommend to change the password of your Microsoft account, and enable two-step verification if you haven't already.

Change Password of Account in Windows 10 User Accounts Tutorials

Turn On or Off Microsoft Account Two-step Verification User Accounts Tutorials

 

Strange Windows 10 User Account issue.

Unfortunately I had done those steps numerous reboots, it just, reappears for no good reason. The base account isn't even a Microsoft account, it's a local account.

I haven't quite tried the built in administrator account on W10, but so far in my experience on my own computer, the built in account seemed to have absolutely no more control than I did on my own.

It's just strange, I go in, it warns me twice about deleting the account, then it's gone. Reboot, and it's back?

EDIT: Just to specify, both command line and Netplwiz both say only HIS account exists on the computer, it doesn't list this rogue account. This is what I meant in my first post about the fact that even Windows doesn't seem to believe it exists, HALF the time. *Frown