Thinking about buying an upgrade version of Vista to avoid all the OEM activation rubbish?
But now the prospect of me migrating to Vista is looking even further off. Ken Fisher reports that upgrade keys only work if there is a valid version of XP already installed. A bit of digging reveals this official confirmation from MS. You won't be able to pop in your old XP CD or give it your old XP key to confirm the upgrade validity.
Building a new machine?
Install XP first and then Vista on your new drive.
Drive crash and you need to install on a fresh one?
Install XP first and then Vista.
Fiddled with something and now it won't boot?
Install XP first and then Vista. (Yes - apparently the upgrade DVD will not allow you to boot from it to begin the installation.)
Want to wipe your old disc completely and install Vista on a reformatted drive?
Reformat the drive, install XP, then install Vista. (This is going on the experiences reported here by someone who has an upgrade disc.)
[Edit]Just realised another thing - It still needs to be confirmed whether the old version of XP needs to be activated or not. Given MS's stance on licensing these days, I wouldn't be surprised if that were so. If true, that means that buying an upgrade version will not give you a serially-transferable retail licence of Vista unless you are upgrading from a retail copy of XP. So, if you're thinking about upgrading a machine with an OEM XP Home licence (as I was), there's no point buying the more expensive upgrade version whatsoever.