Here is what i'm talking about from Microsoft Technet.
Step-by-Step: Windows 7 Upgrade and Migration.
Little ways down in the article. " Upgrade from Windows XP to Windows 7"
http://technet.microsoft.com/en-us/library/dd446674(WS.10).aspx#BKMK_UpgradeFromXP
Can you install it on a blank drive. Technically yes. You just repartition, and reformat with your older OS, install it bare bones, than do a clean Windows 7 install and delete the Windows.Old file. If you have repair discs then do a bare bone install with that.
I'm sure if you decide to go back to you original OS. You wil be able to reactivate it. If your drive goes, than you may have to call MS, or if it goes past 120 days you may be able to reactivate online. I'm sure they will not deactivate the old OS. Large companies would'nt go for it. Especially...
Well let me see. If you get Home Premium and install Virtual Box or VMWare, then you try to use the same disc that you applied to your upgrade. It will not allow you to activate it, since you will be activating it twice. So yes it will be DEACTVATED. This was also mentioned on Paul Thurrotts...
Here is some PROOF.
http://community.winsupersite.com/blogs/paul/archive/2009/07/09/clean-install-with-windows-7-upgrade-media-how-does-that-work-exactly.aspx
Chris P.. from the article works for Microsoft.
Emphasis " If you do not have a qualifying Windows operating system installed...
Quote: "Everybody wants a concrete clarification on how it will be before Oct 22"
Your right about that, but knowing Microsoft we won't find out until after Oct 22, when it's to late to cancel our orders. And old business trick. Remember all Microsoft really cares about is your money, not your...