Compiling a C header file in Win8 64 bit

Today by mistake I compiled a C header file (*.h). The first I knew of this was when an error message box appeared telling me this version of Windows did not support 16 bit applications.

At this point I was unaware that by mistake I had compiled the header file and not the intended .c file (with the main function). I thought it was my code not working and I started to Google search this error.
Only after spending ten minutes searching did I look at what I had done again in Geany4Windows and notice I had compiled the wrong file!

Of course when I compiled the intended *.c file all was well as a binary file was created….