Hello Don G.
I had the same problem some weeks ago, and posted the solution in this forum, but it might be hard to find now, So, here again is the way to upgrade Vista Home Premium to Vista Ultimate, 32 bit, when the upgrade goes on and on, but then quits right at the end. This I got from Microsoft support. The solution is easy and not obvious. For this Anytime Upgrade from Home Premium to Ultimate -- Go to Control Panel > Programs and Features.
On the left side, if I remember correctly, click on "Turn Windows features on and off." Turn off these three things:
Microsoft.NET Framework 3.0
Remote Differential Compression
Windows DFS Replication Service
That is probably enough, but Microsoft also said to be on the cautious side, from msconfig, uncheck "load startup items" and check "Hide all Microsoft services." (You can turn all this stuff back on, if need be, once Vista Ultimate is installed.)
Now you are all set to upgrade to Vista Ultimate. Make sure that you have downloaded to your computer the small file from Digitallocker. Then put your Vista DVD into your DVD drive and follow the simple instructions. This should work and after one and one-half hours or so, you will will Vista Ultimate installed. It is very nice, especially DreamScene.
The above took me a good 10 hours of phone call after phone call, going in circles, until a Microsoft engineer in India took pity on me and said she would stick with me until my problem was solved. As you can see, the solution is very easy, but who would figure it out by them selves? Or know why it works. But it works, and that is enough.
This problem must be widespread; I am making a hardcopy of what I have just typed so to be quickly ready with a reply to others here with this problem. Perhaps you be a on the lookout too and give some one a hand with this exasperating situation.