@El_Heffe said:A few years ago, when I switched from Windows XP to Vista x64, I did a clean install of Vista and then began installing all of my various applications.  Everything went perfectly except for one (very important) application.  Despite the fact that Vista included .Net 3.0, this program would not install, giving me an error message saying that .Net 2.0 was required.  WTF?  Did they hardcode the requirement for .Net 2.0 into the installer?  That's the only thing I can think of.  Once I downloaded and installed .Net 2.0 then the program installed just fine. They have since fixed this problem in newer versions of their installer, but I think it illustrates that the alleged backwards compatibility of .Net is not as fool proof as some would claim.  Except that the application having a hardcoded requirement for .Net 2 is hardly the fault of the .Net system. You yourself said the only explanation you could think of was that the installer was looking for evidence of 2 being installed, NOT that a version of .Net greater than or equal to 2 was installed. Microsoft's developers can't possibly plan for that.