Do I need to format and install the full version of Win7 so my computer doesn't start shutting down sometime next year? I am currently running the Win7 Release Candidate. Or can I just buy the upgrade or full version and change the product key. I am very happy with my computer at the moment and don't want to reformat the whole thing and start over! Just confirming pretty much what I already know, that I will have to reinstall and start fresh.