Upgrade X86 home premium to x64

Boot to DVD and choose to upgrade the X86 install (assuming that's an option) or scrub the existing install and start fresh with X64, in which case presumably the key I used for X86 will be accepted and activated for x64, no?

Do you know that until you come to do this and you search for help on the matter just to comfort yourself that you're doing it right that you find not a shred of help or even a mention of doing this anywhere on MS or in the listed MVP's pages, also no readme or support files on the X64 DVD.............I can't begin to imagine it's possible to have then dual booted and both activated with the same key, but there's no where to tell you what you can or cannot do.

If anyone can find any official edicts from MS regarding this I would be very grateful if you might steer me in the right direction, otherwise I'll just do what I think I should and see what happens.

Answer found in x86 help and support, now why didn't I think of that?

You have to clean install, no upgrade path from any x86 Vista to any x64 so a double install again, mind you the x64 disk doesn't say it's 'upgrade' or 'full' but from the foregoing, logically it can't be an upgrade 'cos it's not possible from x86.

 

Yep the X64 entire OS is very different from the x86. A clean install is necessary. Good find tho, I'm sure someone will ask the same thing and I will point them to this topic.