When installing MS SQL 2012, the installation can hang on the product key page. To get out of this, right click the Task Bar icon for the SQL Server 2012 installation and click Managed SQL Server Installer. This will then prompt you to continue, click Yes and this will stop the installation from hanging. Unfortunately, the SQL Server 2012 installation will not continue and you will be presented with this error:
SQL Server Setup has encountered the following error:
SQL Server 2012 ScenarioEngine.exe and setuppatch.exe cannot be run in this mode. If you are running ScenarioEngine.exe, start setup.exe instead. If you are running setuppatch.exe, run it from the command prompt, as the user interface is not supported for this action. For more information about Setup, see SQL Server Books Online.
Error code 0x84B20001.
The fact that the SQL Server 2012 installation hangs, has been registered with Microsoft as a bug, however this hasn’t really been addressed yet and a workaround has been presented to install SQL from the command prompt (which is actually what the error suggests).