Issue
You were creating a cross-platform deployment, i.e., a 32-bit deployment on a 64-bit OS or vice-versa, and you added two different language packs to the deployment causing the installer to display the following error message and crash:

Solution
When creating a cross-platform deployment, only add one set of language packs to the installer per session of setup.exe. If you need to create the deployment in an additional language, you should do so in a separate session of setup.exe by launching the installer from the media and then adding a single language pack.

Autodesk – Autodesk Revit Architecture Services & Support – 2012: Installer crashes when creating cross-platform deployments with multiple language packs added in a single session of setup.exe

How do you get rid of all the remnants of Revit 2010?

Check out this page at Autodesk Revit Architecture Services & Support.

It’s interesting to see where Revit stores it’s stuff in the Registry.

However, I’m not too sure on the recommendation to ‘Use the End Task feature to end any anti-virus programs’ before reinstalling Revit. Anyone see any complications with this?