From the Start menu, National Instruments->NI-DAQ->NI-DAQmx C Reference Help
If you don't find it, perhaps you need to go back to the installer and make sure you installed NI-DAQmx as well as NI-DAQ Traditional.
John Weeks
WaveMetrics, Inc.
Phone (503) 620-3001
Fax (503) 620-6754
www.wavemetrics.com