 <p>As explained in <a href="http://stackoverflow.com/questions/2921702/change-managed-c-project-to-another-framework-than-4-0-with-vs2010">this answer</a>, you need to add a TargetFrameworkVersion by manually editing the .vcxproj file.</p> <p>I have VS2008 installed on that machine but I think I also selected to include the VC90 compilers when I installed 2010.</p> <p>However, it appears it is <strong>not supported by design,</strong> according to <a href="https://connect.microsoft.com/VisualStudio/feedback/details/560606/c1001-compiler-crash-on-c-cli-project-in-vs2010-when-target-framework-is-3-5" rel="nofollow noreferrer">this Microsoft response</a>: <em>targeting the 3.5 framework with the Visual C++ 2010 compiler is not supported. The Visual C++ 2010 compiler only supports targeting the 4.0 framework.</em></p>