Please try these steps instead with installing new build:
1. Clear the content of the directory under C:\users\your_username\Appdata\local\temp. For whatever reason, not all temp files automatically remove themselves and is NOT usually caused by Nitro Pro files.
2. Download and run our Clean Up utility to uninstall your Nitro Pro: http://install.nitropdf.com/support/downloads/cleanup.zip
NOTE: This clean-up tool will erase any existing signature files within Ni
These exact steps should be taken when installing Nitro Pro produces error "Nitro Setup Wizard has failed"