The GPIB driver in Win 9X/ME allows the system to use GPIB-ENET and PXI-GPIB controllers at the same time.
However, in Win NT/2000, the driver is separate for PXI-GPIB and GPIB-ENET. Only one controller can be used. You can use either the PXI-GPIB or GPIB-ENET, not both.