This function sends a WM_DDE_INITIATE message to all top level frame windows. These are windows registered with CS_FRAME, whose parent is the desktop window. No message is sent to object windows.

The WinDdeInitiate function does not return to the client application until all receiving applications have, in sequence, processed the WM_DDE_INITIATE message, and the client application has received all the corresponding WM_DDE_INITIATEACK messages (see WinDdeRespond).

To support DDE conversations between applications running in different memory models (16-bit and 32-bit) it is necessary to process all DDE messages in the application window procedure. The use of the WinDispatchMsg function ensures that conversion is performed on memory or segment addresses.