INT 61 - PC/TCP kernel v2.05+ - "net_shutdown" - UNINSTALL
        AH = 10h
Return: CF clear if successful
        CF set on error
            AX = error code (see INT 61"PC/TCP")
Note:   this function is not supported by Beame&Whiteside's BWPCTCP v3.0a shim
SeeAlso: INT 61"PC/TCP",INT 61/AH=00h"PC/TCP"

.