Can or how do you install software to another computer?

I thought my sister or somebody installed microsoft 07 to my desktop from a cd that she burned the real version from at her place. Can you do this? I thought you could..and if so how? I have the program/software paperport on my desktop and had a blank cd and burned it onto my blank cd or thoughts so..it was on "make a data cd" for the setting for my burner nero essentials. But once I the cd in my laptop it was there on the cd but it said "action is validated only for software already installed" or something like that. I thought there would be an install set up there.