If the OpenGL key is not there, then it has not changed from its default value of 16 for DirectX. You can add it as as DWORD. Also, if you use Settings > App Data Directory > Set…, then it no longer uses the registry except to note that there is an app data directory and then it uses shotcut.ini in the app data directory. The old registry values are kept in case the app data directory goes away.
See also Display Method