Well, you can not change your name in the Steam version, either (it is just less of an issue because the name people pick for Steam is intended to be used for gaming, and possibly online multiplayer).
Yes you can, since you can change your steam name to whatever you'd like and that is what is being used in game. However, you can also change your pc's name.
Here's how:
Change pc name on win7/vistaThere you go, a quick reboot and you'll have a different name in game.
Granted, using an option for this in-game would be faster and better, but as a temporary solution this also works.