ASP.NET 4 was not registered in IIS. Had to run the following command in the command line/run
32bit (x86) Windows
%windir%\Microsoft.NET\Framework\v4.0.30319\aspnet_regiis.exe -ir
64bit (x64) Windows
%windir%\Microsoft.NET\Framework64\v4.0.30319\aspnet_regiis.exe -ir
Note from David Murdoch’s comment:
That the .net version has changed
since this Answer was posted. Check
which version of the framework is in
the %windir%\Microsoft.NET\Framework64
directory and change the command
accordingly before running (it is
currently v4.0.30319)