Today I ran the amdwgmigr.exe directly and not from the shortcut. It ran! It gave a repeated error: " parameter incorrect" It opens AutoCAD Mechanical (not MDT) and does purges and some other work before trying to save. ACAD gives an error on the save attempt saying the MDT files cannot be modified in AM. The save is disabled. I got a dialog box to send an error message to AutoDesk. I immediately received an email with a hotfix which I installed by copying the two .dll files to replace the existing ones. (Open-Save hotfix.). Afterwards, I still had the same problem trying to migrate files.

ok, here are the results of what I learned:
How to use the file migration utility to migrate files from old MDT (e.g., MDT3) to new MDT (e.g., MDT2009)
The batch migration utility is very handy but it doesn’t work perfectly. You’ll need some patience and persistence.
First, disable your firewall or be prepared to allow the MDT and AM to talk to each other.
Do a test file first and then do a few files at a time. If a file makes the program crash and it doesn’t work any more (i.e., I tried running MDT again and then the utility – it didn’t work: Before proceeding to the second screen, a dialog box gives a safety warning: "If you have not yet backed up your files please exit and backup before proceeding" with 2 buttons, 'exit' and 'continue.' Clicking on either one closes the utility.), repair MDT2009 and try it again. You might have to do this several times; I left my MDT2009 installation disk in the drive. If it
Some problems you might encounter:
It opens AutoCAD Mechanical (not MDT) and does purges and some other work before trying to save. ACAD gives an error on the save attempt saying the MDT files cannot be modified in AM. The save is disabled..
I was able to update my MDT2009 to sp3 but was unsuccessful in installing the hotfixes. They weren’t necessary.

Edited by: cvbt-thailand on Nov 17, 2009 9:00 AM