I have an app that uses the MSBuild task, which calls aspnet_compiler which then spawns csc.exe. On my local machine, which is WinXP SP3 with .NET 2.0 & 3.5 & MS Visual Studio 2008, aspnet_compiler correctly spawns csc.exe from the 3.5 framework. However, on the production server, which is Win 2008 with both .NET 2.0 & 3.5 installed, it spawns csc.exe v 2.0, which gives a lot of compile errors. Note that I'm just running the aspnet_compiler from an NANT script to compile & merge the app to a DLL to be deployed later, not deploying it to the IIS. Is there anything I can do for using the 3.5 framework? Also, I looked into IIS config and the 3.5 framework is not listed there at all as an option to use. There's just 2.0 or no managed code.