Summary: How to fix the installation Error 1921
Related installation help: Troubleshooting Rhino 5 Installation

The log file shows “Error 1921. (1)Service 'McNeel Update Service 5.0' (McNeelUpdate) could not be stopped. Verify that you have sufficient privileges to stop system services.”

Solution 1:

• Reboot Windows and run the installer again. The Update Service starts when Rhino is launched so it will not be running after a restart.

Solution 2:

• Manually stop the service
  1. Run services.msc
  2. Find “McNeel Update Service 5.0”
  3. Right-click and choose Properties
  4. Change Startup type from Automatic to Disabled
  5. Close Services
  6. Restart Windows
  7. Install Rhino
  8. Run Services.msc again
  9. Change the Startup type for “McNeel Update Service 5.0” back to Automatic