It isn’t unusual to find Windows PCs running three or more different copies of .Net Framework. I’ve seen versions 1.1, 2.0 SP 1, 2.0 SP 2, 3.0, 3.0 SP 2, 3.5, 3.5 SP 1, 4 Client, and 4 Full on fairly recent machines. My production machine is currently running .Net Framework ...