"This app has been blocked by your system administrator" when installing software

This error is in fact a legitimate protection Xavier has implemented against malware installation.  This policy prevents installers from unzipping files directly to the AppData folder, a common malware target.

1. Right-click on the software installer.
    
2. Choose 7-Zip >> Extract to "<folder name goes here>" As an example:
   
   
   
    
3. Open the extracted folder. Inside, there should be an installer (usually a .msi or .exe file) among the files listed.
    
4. Run the setup or installer within the extracted folder, and the process should complete without further errors.