Hello Zinefer,
I have tried with this piece of code and I do not have any problem.
#include <windows.h>
int PASCAL WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpszCmdLine, int nCmdShow)
{
MessageBox (NULL, TEXT ("Hello World!"), TEXT ("Hello!"), MB_OK);
return 0;
}
Which version of Pelles C do you use?