ICM_ABOUT

wParam = (DWORD) (UINT) hwnd;
lParam = 0;

Notifies a video compression driver to display its About dialog box or queries a video compression driver to determine if it has an About dialog box.

• Returns ICERR_OK if the driver supports this message or ICERR_UNSUPPORTED otherwise.

wParam

Handle of the parent window of the displayed dialog box.

You can also determine if a driver has an About dialog box by specifying -1 in this parameter, as in ICQueryAbout. The driver returns ICERR_OK if it has an About dialog box or ICERR_UNSUPPORTED otherwise.