Downloading the software doesn't have anything to do with registering it.
Registration is for those who wish to hide the reminder screen which shows when the software is getting old.
I believe the reg function in RRConfig was broken until recently, you should use the tool in this link (From the FAQs):
How do I disable the reminder screen ?
Also I have said this too many times: registration is OPTIONAL, if you keep the software updated it will never show anything.
Running Win 7, CF 4.1, 40 Gig Intel SSD, Visteon HD radio w/ Mitch's cable/software.