Reply from IIS7: http error 500.21 internal server error handler pagehandlerfactory-integrated has a bad module ManagedPipelineHandler
I recently installed a Win7 win VS2010 and IIS7. Unfortunately I installed VS2010 before IIS.
After some other bugs I got something in the line of
http error 500.21 internal server error handler pagehandlerfactory-integrated has a bad module ManagedPipelineHandler
The solution was to reinstalls Dotnet4 with IIS and that is done through aspnet_regiis.exe
or the version you use.
Here is the caveat: you have to run it from a prompt with raised privileges. The output doesn’t give you any clue about this but just outputs its help instead. Typically shift-right-click and start the command prompt as administrator.