If you have an Outlook account on your computer, it’s likely that you’ve set up a registry key to store the account’s settings. If you don’t have a registry key, you can remove the Outlook account from the registry by using the following steps:

  1. Open Registry Editor and navigate to the following location: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Outlook\Accounts<user name><account number>
  2. Create a new key called “Outlook” and give it a value of “1” (the default).
  3. Add another key called “Organization” to the same location and give it a value of “1”.
  4. Add another key called “UserData” to the same location and give it a value of “1”.
  5. Save all these keys in their new locations.
  6. Close Registry Editor.
  7. Start Outlook and sign in with your Outlook account credentials (e.g., your user name and password).

Open Windows Explorer and go to Computer/This PC. Navigate to C:\Users\USERNAME\AppData\Local\Microsoft\Outlook. Delete the . ost file for the account that you want to remove from the registry.

How to remove the Primary Account from Outlook