Unable to progress on Windows XP to Vista upgrade

I'm trying to upgrade Windows XP Pro to Vista Ultimate, and I don't want to do a clean install. The upgrade gets most of the way through the last step in the list of tasks (after about two hours) and then aborts with the following error:

The upgrade was not successful.

It then restores the system back to XP.

When I look in the setuperr.log file (in C:\$Windows.~BT\Sources\Panther, created during the upgrade), the last error in the file is the following:

2009-10-31 21:17:55, Error [0x080390] MIG Failure while calling IPostApply->PostApply for Plugin={ServerPath="%windir%\system32\drmmgrtn.dll", CLSID={743B7FD2-8427-4b7d-B330-A95618DE2BFC}, ThreadingModel=Apartment}.
Error: 0x80070057

I've searched the net for all of the keywords in that error, but haven't found a solution. I've also called Microsoft and paid for a support case, but so far they haven't been able to figure it out either.

I did, however, find a related Super User question, Troubleshooting failed upgrade to Windows 7? about upgrading from Vista to Windows 7.

The file mentioned in the error, drmmgrtn.dll, wasn't on my machine. I can see that it's part of the Vista install (in C:\$WINDOWS.~BT\Sources\dlmanifests\microsoft-windows-mediaplayer-drm-dl) so I'm assuming that the installer is trying to load it but can't for some reason.

Looking at the properties of the file, I can see that it's called DRM Migration DLL, from Microsoft. I tried removing every program I could think of that might interfere with DRM, but it always fails at the same place with that same error.

I've also done the following:

• Used msconfig to boot into Selective Startup mode, with only Microsoft services running.
• Uninstalled AVG Anti-Virus, Nero, Nvidia display driver, Power DVD, and Windows Media Player.
• Copied the contents of the Vista install DVD to the hard drive and run it from there.
• Checked Event Viewer, but found no errors at the time the installation was aborted.

Anyone have any other ideas to try?

Microsoft was right, you should give up and do a clean install. Obviously something carrying over from XP isn't compatible with Vista. While you're at it, skip ahead to Windows 7.

The clean install is your best option since half your apps wouldn't work after the upgrade anyways. Best to inventory them and backup your data and then re-install after putting on the new OS. If you don't have some goofy app from 8+ years ago that's your reason for wanting an upgrade over a clean install, you should also consider Windows alternatives like Linux or Mac.