My client has a server he is looking to sell. When I start it up, it wants me to sign in to one of 2 domains. Unfortunately, these domains do not exist. The server is not even connected to a network. I am just trying to clean off any user files. I've seen before where you choose a domain to log in to, it also says "this computer". That isn't happening here. I also can't boot up in Safe mode. How can I get on the server? It's a Dell Poweredge R710.