William,
It seems there's a lot going on here - I'll try to sort it out with you. First, the Instrument I/O Assistant is primarily for GPIB and serial instruments. If you haven't already, you will need to install the NI-488.2 driver to use that assistant. This is most likely the source of the error you are receiving.
The DAQ Assistant is for DAQ boards. NI-DAQmx 7.0 does not yet support the DAQCard-6024E, however, that board IS supported under NI-DAQ 7.0 Traditional.
I hope this make things a little clearer.