Using Windows 7 Upgrade DVD to perform a clean install

One of the big unanswered questions about Windows 7 is currently ricocheting around the Web: can you install Windows 7 on a clean hard drive using the upgrade DVD? A related question: can you install Windows 7 Upgrade on a PC that is running a, uh, less-than-genuine copy of Windows XP or Vista?

I don’t have a “real” Windows 7 Upgrade DVD in my hands, so I can’t confirm anything that I’ve been reading.

Paul Thurrott says you can do it, but the method he gives is horribly convoluted. (It isn’t clear to me why a slmgr -rearm command would open up anything that can’t be done in a much more convenient way.)

If any of you have the upgrade DVD in hand, could you try a few experiments for me?

- Try to boot from the upgrade DVD.

- If that works, try installing the upgrade on a PC that only contains a completely clean hard drive: Nothing on the hard drive, no other hard drives in the computer.

- Try installing the upgrade on a PC that’s running a pirate copy of XP or Vista. (Or, failing that, a copy of XP or Vista that hasn’t been activated.)

Let me know what you find, and I’ll gladly credit you in my next Windows Secrets Newsletter Top Story.

UPDATE: Ed Bott has some definitive answers. You can bet that they’re quite accurate. Paul Thurrott has published a rather bizarre workaround, and confirmation that the Family Pack upgrade DVD is identical to a “regular” upgrade DVD – the only difference is the type of key.