A virtual device receives this message when the virtual shell device needs to display a message box to the user but cannot use the system virtual machine and Windows functions to do so. The virtual keyboard, mouse, and display devices save their current state, enable any message mode services, and initialize the corresponding device for message mode processing.
Create_VM
This is the first message the virtual device receives when a new virtual machine is created. The virtual devices should initialize data associated with the virtual machine, especially the control block.