Windows initializes the mouse driver by calling the driver's initialization routine, and subsequently calling the driver's Enable function. The initialization routine determines whether a mouse exists and whether an MS-DOS mouse driver is present. If the initialization routine returns a nonzero value, Windows assumes the mouse is present and calls the Inquire function to retrieve information about the mouse hardware. This function returns the mouse information in the form of a MOUSEINFO structure.
Windows calls the Enable function when it is ready to receive mouse input. The Enable function installs the mouse-interrupt handler, replacing any existing interrupt handler. Once installed, the handler retrieves the mouse motion and button status and passes this information to Windows through a mouse-event callback function. Windows passes the address of the mouse-event callback function to the driver when it calls Enable. The driver must save the callback function address and use it whenever it has mouse input to send to Windows.
Windows calls the Disable function to remove the mouse-interrupt handler and restore any previous handler. This occurs whenever the user switches to a non-Windows application or when Windows quits. Windows calls Enable to reinstall the interrupt handler when the user eventually switches back to Windows.
The mouse driver includes the MouseGetIntVect function that Windows or utilities can call to determine which interrupt vector the mouse hardware is using.