If you want to use plain C language, you should choose "Win32 console application" type of project.
Besides that, "winmain" must be "WinMain". As you know, C is case sensitive. Also, the prototype for WinMain does not accept void as parameters.
Another mistake in your code is the string "c:\test". The backslesh is reserved character inside character strings. If you want to have one backslesh, than you have to use "\\". So, your string becomes: "c:\\test".
Here's the code that works if you start with Win32 console app projects:
#include <windows.h>
void main(void)
{
int nTemp;
nTemp=MessageBox(NULL,"Hello World",NULL,MB_OK);
}
------
#include <windows.h>
#include <stdio.h>
void main(void)
{
FILE *filehandle;
filehandle=fopen("c:\\test.txt","w");
fprintf(filehandle,"%s\n","Hello World");
fclose(filehandle);
}
Vlad