Int 16 Fn FFEF  U - Pc Tools V5.1-8.0 Desktop - Installation Check         [U]

   AX = FFEFh
   CX = 0000h

Return: CX = ABCDh if PC Tools DESKTOP.EXE installed
       BX = segment of resident portion
       AX = ??? (v5.1/5.5 only)

See Also: AX=FEEFh,AX=FFC5h,AX=FFF3h