Windows 2008 Unauthenticated

We have a virtual server setup running Windows 2008 Unauthenticated, but we need to be able to have at least 5 users logged in via remote desktop all at the same time.

What is the best way to do this? I believe I require additional SALs for each user, however do I also need terminal services setup as well? Or is there a way I can do it without terminal services?