Open a windows command line. Switch directories to C:\Windows\Microsoft.Net\Framework\v4.0.xxxx
where the x's are the build number. Type aspnet_regiis -ir
and hit enter. This should register .Net v4.0 and create the application pools by default. If it doesn't, you will need to create them manually by right-clicking the Application Pools
folder in IIS and choosing Add Application Pool
.
Edit: As a reference, please refer to the section of the linked document referring to the -i argument.