Sorry I totally forgot about this. the actual function was exported, except it was not implemented. It is now. $V7Voldll = "W7VVol.dll" _SetMasterVolume(77) MsgBox(0, "Result", _GetMasterVolume()) Func _SetMasterVolume($vol); 0 - 100 DllCall($V7Voldll, 'long', 'setvol', 'float', $vol / 100) If @error Then Exit MsgBox(0, "Error", @error) EndIf EndFunc ;==>_SetMasterVolume Func _GetMasterVolume() $aDllCall