The CPL_INIT message prompts a Control Panel dynamic-link library (DLL) to perform global initialization, especially memory allocation.
lParam1
Not used.
lParam2
Not used.
The Control Panel DLL returns nonzero if initialization is successful. Otherwise, it returns zero. If the DLL returns zero, Control Panel calls the FreeLibrary function and ends communication with the DLL.
Because this is the only way a Control Panel DLL can signal an error condition, the DLL should allocate memory in response to this message.
This message is sent immediately after the DLL is loaded.