A progress bar is a common control that indicates the progress of a lengthy operation by displaying a colored bar inside a horizontal rectangle. The length of the bar in relation to the length of the rectangle corresponds to the percentage of the operation that is complete.
Progress bar
You create a progress bar by specifying PROGRESS_CLASS in the lpClassName parameter to the CreateWindowEx function. This class is registered when the common control DLL is loaded. You can use the InitCommonControls function to ensure that this DLL is loaded.
To register the progress bar class using the InitCommonControlsEx function, specify the ICC_PROGRESS_CLASS flag as the dwICC member of the INITCOMMONCONTROLSEX structure you pass in the lpInitCtrls parameter.