Install program as root user

I downloaded a program from Broderbund's web site. The .dmg install file is in my Downloads folder. When I try to install the program, I get a message that says, "You must be logged in as a root to install this program." I Googled and followed the instructions to Enable Root User through System Preferences, Users and Groups, etc. I logged out as me, then logged back in under "Other", then "root" using the password I assigned. It seemed to work, as my desktop was different, etc. However, as such, the .dmg I downloaded when I was logged in under my own name was not in the Downloads folder for "root", which I was afraid of. How am I to install the program?