Windows 10: Hwo do i remove "accounts used by other apps"

Hi all,As picture below:

:)

 

Remove account

I suggest you backup your personalized files first before removing the account.
To delete an account, follow these steps:

1. Press WIN + X keys and click Command Prompt (Admin) from the menu.
2. Type the following command and press Enter. Replace test with the name of your sister's account. Code:

 

Cannot remove Mail app account

Hi,

For us to provide the appropriate troubleshooting step to resolve the issue, we'd like to ask for additional details. Please answer the following:

• Have you made any recent changes or installed updates before this issue occurred?
• Are you also getting an error message when trying to remove the email account?
• What troubleshooting steps have you tried so far?

For initial troubleshooting, we suggest running the Windows App Troubleshooter.

We look forward to your response.

 

Need help with permanently removing accounts from Mail App

This is a shared PC and I want to either remove the email accounts that are associated with the Mail App permanently or to deactivate the automatic sign in (if there is one).

I've gone to Manage Accounts - Delete Account from this device. It tells me that the account has been successfully deleted from this device.

YET it will reactivate the account (without me entering a PW) if I choose to Add Account, it lists suggested accounts that can be added, which in this case, it lists our Outlook accounts. If I choose an account to be "added" it adds my Outlook account to the Mail App, and SOMEHOW it knows what the PWs are and automatically signs in and opens the accounts. I can see everyone's emails just by re-adding their accounts!

How do I solve this issue please! I have thought of uninstalling the Mail App, but if someone who shares the PC decides to install it, they will see everyone's email.