HTTP Error 403.14 in IIS 7.5

I get this error the first time I try to set up IIS for local development on a new 64-bit Windows install.
Turns out, ASP.NET 4 isn't yet properly registered with IIS. To do so, run the following from an administrator-level command prompt:

%windir%\Microsoft.NET\Framework64\v4.0.30319\aspnet_regiis.exe -ir

Do the same for a 32-bit Windows install except with s/Framework64/Framework/.