I just took my ETS TOEFL test today.
I was surprised to see that in Internet Explorer, not only right click was disabled (which is quite easy), but the entire IE was locked (favs, menus, toolbars, refresh button, etc.)...all controls were locked and one could only use navigator / white area for viewing/typing/clicking.
Initially I thought, that they were using a custom-made browser and used a snap of controls of IE until I pressed CTRL+ALT+DELETE combination (fortunately that was working!) and found iexplore.exe was running!
How could that be done? Disabling entire IE, or rather empowering IE.