Problem Installing 64 Bit Vista Ultimate

I just received my new Dell XPS laptop from the Dell outlet today. It came with an OEM 32 Bit Windows Vista Home Premium installed. Since the system has 4 GB of RAM I want to install my copy of Windows Vista Ultimate with service pack 1. I have the retail upgrade version of Windows Vista Ultimate. This comes with both the 32 bit and 64 bit versions of Ultimate on their own DVD.

I have been booting from the DVD and selecting a clean install. Anyhow, when I try to install the 64 bit version I get the following message: "To use the product key you entered start the installation on a computer that is running a genuine version of windows." Incidentally, it does let me do a clean install using the 32 bit version of Ultimate which I did. Now I want the 64 bit version. Any ideas?

 

i thought you couldn't do upgrades with 64 bit os. i think you need to do clean install.

 

Yes, clean install is the solution, some have done 3 clean install before it works, that's why it's called sp"3"

 

I believe the retail 'upgrade' won't update an OEM installation. If you buy a 'full' install retail version of Vista x64 you can upgrade the OEM one as I did. I would recommend clean installation if you do get the full not upgrade version.

 

There is a workaround for this problem. Guide is posted here:
http://www.winsupersite.com/showcase/winvista_upgrade_clean.asp

But you cannot "upgrade" from a 32-bit to a 64-bit OS. Only a clean install, so make sure you have everything backed up.