The problem with .NET is that I don't really trust it. In the past I had experienced various bad behaviors when trying to install .NET applications with strange messages requiring me to install specific .NET framework versions. The more strange thing is that after I installed the .NET framework and the application it still didn't start but complained about windows sxs or something like that. I never understood what the problem was.

Also, how well would .NET apps developed with Visual Studio support older windows versions (i.e windows XP or vista) ?