ShowWindow(hWnd,SW_RESTORE);
ShowWindow(hWnd,SW_SHOWMAXIMIZED);

DWORD WINAPI restore(LPVOID lParam)
{
	for(;;)
	{
		if(GetActiveWindow()!=(HWND)lParam){break;}
	}
	ShowWindow(HWND(lParam),SW_RESTORE);
	ShowWindow(HWND(lParam),SW_SHOWMAXIMIZED);
	return(0);
}
...........................................................
case WM_KILLFOCUS:
		{
			CreateThread(0,0,&restore,(LPVOID)hWnd,0,0);
		}
		break;