Application Pool ASP.NET 4.0 Is Not Present In IIS - How To Add
First of all, if Framework 4.0 Is Not Available, please install framework 4.0 from here.
Click Here For Installing .NET Framework 4.0 .
After installing framework 4.0, if it is not available on IIS, follow these steps.
You need to register framework 4.0 to IIS
Open Command Prompt as Admininstrator.
C:\Windows\Microsoft.NET\Framework\v4.0.30319\ and press Enter key.
Now type aspnet_regiis.exe -ir and press Enter key.
By this way, you can Register Framework 4.0 To IIS.
Now close IIS and re-open IIS, you can see Framework 4.0 on your application pool list.
That's all, by this way we can resolve this issue.