Program Install and Uninstall Troubleshooter Tool (Fix it portable)

Some of you have had problems installing Revit.  Perhaps running the Program Install and Uninstall Troubleshooter via Microsoft Fix it portable will help?

I recommend using the following link. After downloading, you will have to run the exe, which itself will then download 'Fix it portable' to a folder that you select:
Portable Offline: MicrosoftFixit-portable.exe

In the top list, click on Install or upgrade software or hardware, and click 'Run Now' next to Diagnose and fix program installing and uninstalling problems automatically.

via
Program Install and Uninstall Troubleshooter Tool Replaces MSICUU2 | Raymond.CC Blog