I can't speak to windows 7. But, I have a 10 year old pc downstairs which doesn't have a user, it has a name, say X. So, I bring up rdc and put in X in computer name. I then hit return (for user) and return (for pswd) and voila, I'm in.
You can also config the login from remote desktop to automatically populate user name: machinename\\username, then, at least in remote desktop, you are brought directly into pswd, hit return. You might want to look that up because in mapping network drives from a cmd prompt user requires / not \\ and I'm dyslexic so I frequently get that backwards (actually, 50% of the time!)
Again, I don't know win7 and I don't know live mesh, however, I would be learning right now if I had bought an Assassin PC.... as per page 1. Why is it I'm always going back to page 1?