关于WinAPI的问题

#include <stdio.h>
#include <windows.h>

int main()
{
    char* pWindowName = "e.exe";

    HWND hWND = NULL;

    hWND = FindWindow(NULL, pWindowName);
    if(NULL == hWND)
    {
        printf("Error : %d\n", GetLastError());
        return 0;
    }

    printf("ok\n");
    return 0;
}