Unable to use PC Game Pass on new PC due to my Office 365 being on another account

Maybe something was updating in the background

If you face something similar in the future, try the next. For now, take care:
Press Windows + X, then click on Windows Powershell (Administrator)

Then type or copy/paste this command and press enter:

Get-appxpackage Microsoft.XboxIdentityProvider | Remove-AppxPackage

Restart your PC and install the recently deleted app:

https://apps.microsoft.com/store/detail/xbox-id...

Finally go to Windows Settings > Apps and Features > Xbox app > Reset and Repair, then restart your PC and give it a new try.

If that doesn't work please also try these tutorials:

https://support.microsoft.com/en-us/windows/fix...

https://support.microsoft.com/en-us/account-bil...

Or try this (RainingRoses response):

"Try the following options for Windows 10/11:
1. Go to Credential Manager (https://support.microsoft.com/windows/accessing...) > Windows Credentials (not the Web option), select XblGrts|DeviceKey and remove.

2. Go to Settings > Accounts > Email & accounts. Select your account with the issue and verify that the ‘Apps need to ask me to use this account’ setting is enabled. This would especially help if you have multiple accounts as you would have the option to choose the correct account on startup, but you can always change it back to the automatic option if you prefer. You can also try to remove the account from here and re-add it later.

3. Follow this file path: C:\Users\[Your Username]AppData\Local\Packages\Microsoft.XboxIdentityProvider_cw5n1h2txyewy\AC\TokenBroker
Delete the Accounts and Cache folders, which will be deleted from the Xbox Identity Provider

Note that the highlighted code in this file path depends on your system so may vary.
If you don’t see a particular folder, then confirm there’s no search filters applied and select ‘show hidden items’, or you can just search for the folder in the search bar.
Restart your PC after trying the above steps, so that these properly take effect next time you sign in. It may also help to then reset and repair and/or uninstall and reinstall the Xbox apps where this error occurs."

Source: https://answers.microsoft.com/en-us/xbox/forum/...

Hey Josef thank you for the reply.

This is a tad embarrassing but yes it had been just automatically logging me into the other account and not allowing me to select switch accounts, but this time when I went in in hopes of getting a screen grab and tried it it actually worked! So I am just going to say you scared it into cooperating so thank you!

Hi and thanks for reaching Microsoft Xbox gamer's community. My name is Josef.
I'm an Independent Advisor and a Microsoft Xbox user like you.

Hope you're doing great today despite this Teeruk

Just to let you know, Microsoft accounts can't be merged or content transfered between them.

About your second question, in order to use the game pass subscription you just need to sign in with the account that owns it on both Microsoft store and Xbox PC app

Are you not able to do it? Or what happens when you sign out and try to sign in?
The previous account logs in automatically?

Do you have any outstanding subscriptions that are past due? Game pass, xbox live, office 365?

If you have Office 365 Family and your son has his own PC you send him a sharing link in order that he can install 365, he doesnt as such have his own 365 Office MS Account. And you can cancel/terminate his 365 via your MS Account at any time