In WinMain under the Windows field defines: For the small icon, we have no proboblem switching ICON_T3DX to something else. The change works right away. winclass.hIconSm = LoadIcon(hinstance,MAKEINTRESOURCE ICON_T3DX)); However, when we change ICON_T3DX to something else for the main icon, the change is not relflected in the actual application. Even when we move the .ico file for T3DX, the application still uses it. The only way we can get it to change is to totally delete every reference to T3DX. Anyone know what is going on? Bad: winclass.hIcon = LoadIcon(hinstance, MAKEINTRESOURCE(ICON_T3DX));