%windir%\Microsoft.NET\Framework64\v4.0.30319\aspnet_regiis.exe -i
If I had been on a 32 bit system, it would have looked like the following:
%windir%\Microsoft.NET\Framework\v4.0.21006\aspnet_regiis.exe -i
%windir%\Microsoft.NET\Framework64\v4.0.30319\aspnet_regiis.exe -i
%windir%\Microsoft.NET\Framework\v4.0.21006\aspnet_regiis.exe -i