This call deregisters a video subsystem previously registered within a session.
VioDeRegister ( )
rc (USHORT) - return Return code descriptions are:
| 0 | NO_ERROR | 
| 404 | ERROR_VIO_DEREGISTER | 
| 430 | ERROR_VIO_ILLEGAL_DURING_POPUP | 
| 465 | ERROR_VIO_DETACHED | 
| 494 | ERROR_VIO_EXTENDED_SG | 
Remarks
VioDeRegister must be issued by the same process that issued the previous VioRegister. After VioDeRegister is issued, subsequent video calls are processed by the Base Video Subsystem.
#define INCL_VIO USHORT rc = VioDeRegister(VOID); USHORT rc; /* return code */
EXTRN VioDeRegister:FAR INCL_VIO EQU 1 CALL VioDeRegister Returns WORD