Hendry,
First of all, what is the model of your PCI data acquisition board? Depending upon your board model, you may want to use NI-DAQ 7.0, since that will allow you to automatically install support for LabVIEW 6.i. NI-DAQ 7.2 should work with LabVIEW 6.i, but you may have to manually copy some files to appropriate locations. With your current installation, does your board show up in MAX? If so, can you run any of the data acquisition examples that ship with LabVIEW?