It turns out that SQL Server has a report you can run which will show which features are installed.
The report is run from the SQL Server Installation Center which is available from the Windows Start menu. Click on Tools and then on Installed SQL Server features discovery report:
If necessary, choose how you want to open the file, by selecting the browser of your choice:
The report will open and show all of the installed features:
This report is going to be very useful; in the past I’ve had to go away prodding through various folders or utilities to see if the necessary features were installed. Now, with this one report, all of the information is available in one place.