Hi, @gty. These look like permission issues from the OS when running the Git Credential Helper install commands.
Have you tried running this in a Powershell instance with Administrator level permissions?
Edit: I don’t think running that as admin is a good long-term solution but it would rule out OS permissions if it still doesn’t work. However, if it still doesn’t work as admin I would expect a different error at least so please let us know if that changes anything or if there are other questions.