Int 2F Fn 4653  - F-prot V2.x - Virstop - Installation Check               [-]

   AX = 4653h ('FS')
   CX = 0008h

Return: AX = 5346h if installed
       BX = version???
       DS:SI -> ASCIZ name of file containing virus signatures
       DS:DI -> 80-byte buffer for ???