Family Atlas is asking me to register each time I start the program

Do a right-mouse button click on the Family Atlas icon and then look for a menu item that says "Run as Administrator". If you don't find that then click on the Properties menu and then in the window that opens find the "Run as Administrator" checkbox and make sure to put a checkmark in the checkbox.  You only need to do this the first time you run the program (when you enter the registration key).