If you try to publish an ASP.NET web site in a computer on which ASP.NET wasn’t completely installed, you may face this annoying error:
HTTP Error 500.21 – Internal Server Error
Handler “PageHandlerFactory-Integrated” has a bad module “ManagedPipelineHandler” in its module list

You can sort it out by fully installing ASP.NET. Open command prompt (Start > Run > cmd
) and type the command following:
%windir%\Microsoft.NET\Framework64\v4.0.30319\aspnet_regiis.exe -i
