The reflection sample assumes that the C# compiler (csc.exe) is reachable from your PATH environment variable. If you are using Visual Studio, you can make sure that it is in your path by executing the Visual Studio Command Prompt shortcut in your start menu.
From the command prompt, change your current directory to the directory containing the reflection sample.
Build the application by executing make.bat. This batch file will invoke the Visual C# compiler to produce the output file - Reflection.exe.