If you have all the necessary software drivers installed, there should not be any specific settings that are reuqired to enable interrupts. Have you verified that you have the same version of SW installed on both systems?
LabVIEW
LabVIEW FPGA module
VISA
NI-RIO
Do you have any other cards installed on your Pentium 2 system that could be causing an interrupt conflict with the RIO card?
Christian L
NI Consulting Services
authored byChristian L, CLA
Systems Engineering Manager - Automotive and Transportation
NI - Austin, TX