Int 2F Fn 3901  - Kingswood Tsr Windows - Add Or Remove User               [r]

   AX = 3901h
   BL = 0Bh
   CL = number of users increment: +1 if adding a new user
                   -1 if removing a user

Return: AX = error code (0000h if successful)
   SI,DI,DS,ES preserved

Note:  the TSR windows resident module may only be removed when the internal
     user count is zero

See Also: AH=39h/BL=00h,AX=3901h/BL=02h