I purchased a copy of Vista Ultimate (paid upgrade price at Best Buy, but the box and disc don't mention where it is an upgrade or full version) near launch time for a laptop running XP that has since died. I purchased a Dell Slim and would like to upgrade the version of Home Premium that came with it to Ultimate without wiping the drive as I'd like to avoid reinstalling all of my programs and customizing the system. The problem: When I insert my Ultimate disc, enter the key, etc., the option to upgrade is disabled and I'm told to boot off the disc and do a clean install. I want to avoid this. Is there a way of forcing the installer to allow me to perform an upgrade install instead of a clean install? Thanks.

I believe preinstalled Windows are nonupgradable. It is designed to die with the PC on which the OS is installed. i_Xp/VistaUser

It looks as if you have a full version, upgrade disks are plainly labelled on the box with a red background and the disk itself is also clearly marked as an upgrade. It's usually the other way around, people wanting to clean install using an upgrade disk. A quick Google finds that upgrading with a full disk can work, but there seems to be too many problems associated with it, (these all seem to be brand name pc's). If there are must have extra's in Ultimate, then it may pay to clean install. Hang on and see if anyone here has any experience doing it your way.

Well, I managed to get Terminal Services and Remote Desktop to work - since I don't need Bitlocker or Dreamscape, I don't think there's much point in installing Ultimate.