What is the process for installing SP1 after RC1 install?

[nikemen]

For upgrading to VISTA SP1 after having done the SP1 RC1 install months ago?

So, I did the upgrade back in February I think, to SP1 RC1, but now my system shows that I need to INSTALL a LICENSED operating system with a count down timer in days.

What is the process for UN-INSTALLING RC1 to INSTALL the OFFICIAL SP1 if indeed that IS the process one should follow? Has anyone had to do this?