>W98,n=fopen("com2",2) -> invalid seek offset.
>In nt4.0 it works fine.....

If this is VFP, it doesn't really permit serial comms using FOPEN; use the MSCOMM32.OCX.

In FPDOS/FPW, you can do limited comm port access via FOPEN, but now youy run into platform variations in how to specify a port; Win9x expects a trailing ":", while NT and Win2K do not. If the following works under NT:

n=FOPERN('COM2',2)

Win9x expects:

n=FOPEN('COM2:',2)

the same applies to specification of printer ports (LPT1) or standard devices (PRN, CON).