Fatal error: "No Target Architecture" in Visual Studio
Use #include <windows.h> instead of #include <windef.h>.
From the windows.h wikipedia page:
There are a number of child header files that are automatically included with
windows.h. Many of these files cannot simply be included by themselves (they are not self-contained), because of dependencies.
windef.h is one of the files automatically included with windows.h.
Another cause of this can be including a header that depends on windows.h, before including windows.h.
In my case I included xinput.h before windows.h and got this error. Swapping the order solved the problem.
Solve it by placing the following include files and definition first:
#define WIN32_LEAN_AND_MEAN // Exclude rarely-used stuff from Windows headers#include <windows.h>