I just picked this game and I am really enjoying it, one problem I have is that my young son also thinks it is pretty cool
Is there a way for each of us have a campaign going at the same time? That way I can play and still let him mess around with his own games (without impacting mine!)
I guess another way would be to create a second user account for him, and install the game on that for him (if it's not already installed for all users). Since the progress is stored in the Users (usually C:\Users\<Username>\AppData\Roaming) folder on Windows this should create separate save files for him. I guess a normal user account (not admin) suffices for that (if you install it for both users on your account). BTW, the method described by Tomislav above can also be used to backup game progress (to make sure you don't lose it in case of PC problems).