Int 2F Fn BF00  - Pc Lan Program Redirifs.exe Internal - Installation Che  [N]

   AX = BF00h

Return: AL = FFh if installed

Note:  this function is also supported by NetSoft's DOS-NET v1.20+; however,
     none of the remaining BFxxh calls are supported

See Also: AX=BF01h,AX=BF80h,INT 2A/AX=4147h