EBX: Contains a Windows VM Handle.
EBP: Points to the Windows VM's Client Registers.
Save anything that you use.
This routine is called during the display driver's call to the Main VDD function VDD_DRIVER_UNREGISTER. This routine allows the mini-VDD to unhook trapping and/or set flags when the display driver's Disable routine is called by Windows, either during Windows shutdown, or in response to a Windows application wanting to go full-screen (the Windows MediaPlayer application is an example of this). Also, this function is called when going into single-MS-DOS-application mode. The mini-VDD should free all of its trapping and set flags so that RESTORE_REGISTERS and SAVE_REGISTERS do not do anything so that the application has free and clear access to the hardware.