Perhaps IF the registration # was for this program maybe the register button may disappear. After I entered the number, it said "Thank You for registeration of "PHOTO STAMP REMOVER!"
I am not sure if this would make a difference or not, but when I entered the serial number for registration, the program said "Thank You for registration of Photo Stamp Remover!"
So maybe if we were registering the correct program, maybe the register button would go away, I don't know, but I am guessing we may not have a working program at the end of trial period.