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

Solution 2:

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.

1. Download PsExec from Microsoft TechNet, and extract the contents to your desktop.
2. Open a Windows command shell.
3. Change directories to your desktop.
4. In the command shell, enter psexec -i -d -s c:\windows\regedit.exe. This causes Windows to run the registry editor with the permissions of the System account – an account even more powerful than Administrator.
5. Browse to HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Installer\UserData\
6. Right-click the UserData folder, then click Permissions…
7. In the Permissions for UserData dialog box, click Advanced.
8. Be sure that Administrators has Full Control permissions in this folder, and that Users has Read permissions. There will be other user permissions, too, but Administrators and Users are what matter most.
9. Select the Replace all child object permissions with inheritable permissions from this object.
10. Click OK twice to apply permissions.
11. Install Rhino again.