Here is the gory details. I belong to the Microsoft Action Pack subscription service, which included use of VISTA Business version. This required upgrade would not upgrade a Windows Media Center, so it choose to do a install into a seperate directory. Therefore that was not a real upgrade.
After the successful install, I then used the Microsoft site to pay for the upgrade from Business to Ultimate ($135 +/-). The cool thing here is that the Microsoft DVD has all the versions on it, but they can’t be seen. With the purchase, then a file sent over the Internet unlocks the ability to upgrade.
The Ultimate upgrade goes over the top of the Business Vista.
The one gotcha was that after the install my screen was BLANK (horrors!). This is refered in some of the posts as the new BSOD but instead of BLUE it was BLACK. I had to solve this one, only by accident: my ATI video card had shifted the video only to my TV screen, not my PC screen. So I had to use the TV to download the most recent ATI drivers to get back to two screens.
After that I had to reinstall my apps, including DVDFab.
So far so good (but lots of digging around and the wife was relatively patient for two nights whent he computer went through this upgrade)