I am building a new domain from scratch. We own our pulic domain anme example.com. and have publicly hosted website by a third party hosting provider at example.com . I am being told the new domain name should be ad.example.com or corp.example.com ( subdomain) . My concern is that I don't want users to use subdomain.example.com\username for logging in . There is a point in AD setup that asks for netbios domain name and it does not allow me to use "example" and says is already being used, but it does allow me to use the subdomain name (ie ad. or corp). I just don't want to instruct users to use subdomain\username to log in to domain.