Internet Explorer 11 - Emulation Document Mode and User Agent String Drop Down Menu Blank

Hey

I have a user who has a problem with Internet Explorer 11 where when you go to emulation mode using F12, the Document Mode and User Agent String Drop Down Menu are both blank. On our internal website its works correctly but on all other external websites they are both blank.

I have had a look at the link below but this did not help as it would not recreate some of the registry keys.

http://answers.microsoft.com/en-us/ie/forum/ie11-iewindows8_1/document-mode-and-user-agent-string-dropdowns/cd34d5f8-7839-4083-af55-05d49ba85190?rtAction=1387560713451

Charlie