I‘ve searched the web high and low and there is much confusion on this topic. If a user starts with a Windows license, either through a previous version, or perhaps through the recent ‘Express Upgrade to Windows Vista Guarantee’ program, will they be able to use their Vista Upgrade DVD to do a clean install? Many speculate that the DVD will not be bootable, and that you will need to run it from inside your existing OS, so it can validate the license you currently have. Since consumer upgrades are not yet available, there is no way to test this with currently available resources.

This is not to be confused with the legal aspect of an upgrade license. Microsoft has said that if you ‘upgrade’ from XP to Vista, your XP license will still be valid, meaning you could still switch back to XP should you choose to do so (comments section of this page in the Windows Vista Blog). There is also a clear path of which versions of XP can be upgraded to which versions of Vista (Buy a PC Now, Upgrade to Windows Vista After Launch).

So, no speculation here, does anyone reading this know the definitive answer to this question? If so, please leave a comment with the details, and who you are (ie how do you know), or drop me an e-mail (jpfieber@gmail.com). Hopefully we can put this one to bed and get on with our lives!