Just guessing here, but you probably sent them a debug build and they don't have the debug versions of the system DLLs on their system. Be sure that you set your project output to Release before trying to give people your code.
Also if you find any other DLLs in your release folder with your exe, include those as well.
I Doubt you want to go through the hassle of making an install project.
And as far as the makefile project that's nonsense![]()