IIS7: Why can't i Choose v3.5 .net Framework?

Question

The only choices for the application pools are .net 2.0 or 4.0, but my machine is running on 3.5.

I am currently getting a

system.platformnotsupportedexeception

in an app that i built, and i think it might be related to this issue.

Answer 1

Keep in mind, there is no 3.5 version of the .NET runtime - only a 3.5 version of the .NET Framework. The CLR itself is either 2.0 or 4.0. Why they have weird versioning is beyond me (I guess there were no runtime modifications to support the 3.5 framework), but the framework versions are different than the runtime versions.

Answer 2

.NET 3.5 has the same base runtime as .NET 2.0. So in your case, selecting 2.0 is correct.

See this similar question.