If you ever find yourself in a situation where doing a GIT commit/publish/push and get access denied - and you have multiple GIT accounts:

1. Search windows on ‘Manage Windows Credentials’
2. Alternatively, Control Panel > User Accounts > Credential Manager > Windows Credentials
3. Delete any item that references GitHub

The reason for this is that the GitHub for Windows download includes the Credentials Manager which will add credentials so that you do not have to keep logging a username/password each time you do a GIT command. They advertise that they do not cache infinitely but that didn’t prove to be the case with me.

From what I can tell at this moment, this action will need to be performed each time you go from one user account to the other.