Allows the extension DLL to check the installation options as currently set. If any disallowed options are found, the extension DLL should notify the user if not running in quiet mode. Calling TixMessageBox is the recommended method, because it will not display the message box in quiet mode.

Action scheduling

This message is sent by the CheckInstallOptions standard action and may occur more than once, depending on the action sequences used by the installer.


Not used

Result code

If this message is handled, pMessage->lResult must be set to one of the following result codes: