Sounds like you are have a tough time unfortunately!
Obviously this is what Autodesk recommends an i would have to suggest trying these thing too.
"Installation complete. Some products failed to install." during installation of an Autodesk product
But i have had to run a few of these in the past and the only solution was to ensure the uninstall is done using the following;
Always use the Microsoft Uninstall Tool (it is called something different now) as this seems to clean up the messes left behind via Add/Remove method. you may need to search around to find it as they push you down another route called troubleshooter now but it should be there somewhere via a google Search.
When reinstalling ALWAYS use the Browser Method as this gets around any connectivity issues, below is a great link and save me cutting and pasting
How to use the Browser Download method for Autodesk products (imaginit.com)
I really hope this solve your issues but if you are struggling try your reseller of the software or a local reseller they are always a great resource
Jay Colcombe
Autodesk Certified Instructor
Revit Architecture & Structure Certified Professional
AutoCAD Certified Professional
B.Sc. Hons Civil & Structural Engineering
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