I have read your post.
The error message seems to be regarding the admin user rights. In this case I would like to recommend you to please check the status when McAfee is disabled.
To disable McAfee,
Open command prompt --> Type the command netstop myagtsvc
Now check the status.
To enable McAfee,
Open command prompt --> Type the command netstart myagtsvc
please also try the same by login as an administrator.