Summary: How to fix the installation Error 1402 or 1406 (Could not open key: UNKNOWN\Components).
Related installation help: Troubleshooting Rhino 5 Installation
A message “Could not open key: UNKNOWN\Components\(lots of letters and numbers). Error 1402. Verify that you have sufficient access to that key, or contact your support personnel.”
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Installer\UserData\S-1-5-<numbers>\Components key has incorrect permissions.
Solution 1: On the Windows Start menu, enter CMD to the search box. Right-click on the cmd.exe and select Run as administrator. Copy the following line and paste it into the cmd window, press Enter. Then Rhino will be able to install.
secedit /configure /cfg %windir%\inf\defltbase.inf /db defltbase.sdb /verbose
Warning: The following procedure involves editing the Windows registry. Incorrect editing of the registry can damage your computer and cause it to not start. If you are not comfortable performing the following steps, please contact McNeel Support.