We haven't run into this issue before and are trying to get some quick answers w/o doing research.

1) Will a .Net application developed/compiled under an earlier .Net framework ( e.g. 2.0 ) run under a later framework ( e.g. 4.0 )? I.e. will an application compiled under .Net 2.0 is placed on a machine having only .Net 4.0 run properly ( or at all )?

2) If a machine has more than one .Net Version Framework installed on it, will each appliction/dll on the machine run under it's compiled framework, or will the OS run all applications/dlls under the latest framework on the machine?

Thanks,
Bill