Then I heard from one of our users who had taken advantage of Anytime Upgrade; let's call her Jeani. She had decided to purchase the Anytime Upgrade offered on CD that came with her Hewlett-Packard system, shipped with Vista Home Premium. The initial upgrade process itself went uneventfully, but that's just the beginning of this story.
Jeani was having trouble with Vista, so she decided to reinstall Vista on a clean drive. Because her Vista Ultimate was purchased through Anytime Upgrades, it would not install until she first installed and activated the copy of Vista Home Premium that originally came on the computer. Even after a reinstall, the system seemed to develop problems and Jeani reinstalled several more times at the insistence of HP support. All that reinstalling triggered the Vista activation trip wires, and now Jeani has to call into Microsoft to activate each time she reinstalls.
It turned out that Jeani's hardware had problems. HP replaced the motherboard under warranty, but she still has to go through the Anytime Upgrade rigmarole -- including phone activation -- to reinstall Vista Ultimate. This is cumbersome compared with the process with XP, where the setup process merely requires that you prove that you have the qualifying product via a CD, for example. The XP "upgrade" applies to its pricing, but doesn't prevent you from doing a clean install on a bare system.
The consequence is that it isn't possible to use an Anytime Upgrade license to do a truly clean install -- you must riffle-shuffle the new files and registry settings into an existing activated copy of Windows. I'm a clean-install kind of guy, mainly because in all my experience with Windows, I've rarely encountered an upgrade install that didn't end in sorrow and regret for one reason or another. Windows Anytime Upgrades just reinforce those feelings.