I'm not 100% sure, but I believe that you can't upgrade it that way, from home basic to premium? Yes. Changing architecture and basically replacing the whole system? I doubt it, and I would've gone for a reinstall anyways.
I don't think you can? You can back up all your files, photo's and video's etc but you have to reinstall all programs, updates and drivers (assuming the drivers are available for 64bit). At least 18 hours hard slog for me and plenty of grief no doubt due to lost serial numbers for programs I've paid hard cash for etc etc! Not to mention all the lost cookiies, passwords etc......... And for what? A slower gaming PC with serious UAC problems which CTD,s Skyrim all the time?
Convince me I'm wrong. Please! It's been on my mind!
Regards