It is possible to use all National Instruments FF software under Windows 2000. However at this time the only interface board that is supported by the driver is the AT-FBUS card - PCMCIA is not supported at this time.
Starting with version 2.3.5, AT-FBUS board could run FBUS on Windows 2000. And since version 2.3.6(release date is April of 2002), PCMCIA-FBUS interface could run FBUS on Windows 2000. In general, after NI-FBUS 2.3.6, all the interface including AT-FBUS and PCMCIA-FBUS are able to support Windows 2000/XP.