I purchased the 3-license Windows 7 Home Premium Family Upgrade pack from Microsoft Store for $149.99. It was a better deal than I could find on Amazon. All went well until I tried to activate the Windows 7. I’ve got this nasty message that it’s not allowed since this package is for upgrade and not for clean install, though I didn’t have a choice since the hard disk with Vista Windows where I upgraded from crashed and no long accessible and I didn’t want to reload Vista just to wipe it off again. Thanks to Google search and the Option 3 of this link, I was able to activate it without any problem. Honestly, I don’t know why Microsoft is making this distinction between upgrade and clean install as the prices are nearly the same. It just complicates things more and making the users’ lives too difficult especially after the frustration of a disk crash. It’s no wonder Apple is gaining on Microsoft.