Well, y'know, way back when, we had no registration codes, just the software. You didn't "license" it; you bought it. If a newer version came out, you sold or gave the older one to someone else so they could use it. And it was no big deal. Then we got serial numbers to make sure we were indeed the true user, and the numbers became these huge strings of letters and digits that almost guaranteed getting screwed up the first time you write them. Now we have challenge codes as double check for the serial number already given to you on the package. I guess the next generation of all this will be asking my mother's maiden name and DOB as a password to get the challenge code to install the serial number to run the software in the house that Jack built.