title: How come .net 4.0 and .net 2.0 CLR's can exist in a same machine
body: <p>I have a basic doubt that, How can we have both CLR's on a same machine. If this is possible, When I refer few dll's of 4.0 and setting application pool to 2.0 why Cant I run the website(I am getting errors).When we refer the dll's from web.config it means it searches for GAC when that particular 4.0 dll is available in GAC Why dont it load (How come it is not loading).. Please clarify my doubts</p>