Have the boards ever worked in this computer? There are some suggestions for fixing this issue at:
http://digital.ni.com/public.nsf/websearch/01F6913CDF473BFF86256AE2007D92B3?OpenDocument
Check to see if they show up properly in the Windows device manager. Sometimes a bad installation of NI-DAQ can result in similar errors. If multiple copies of NI-DAQ have been installed on the machine, possibly one form LabVIEW and one from a separate NI-DAQ installation, then this can result as well. If this is the case you will need to uninstall NI-DAQ and make sure LabVIEW is not set to install the drivers and then install NI-DAQ 6.9.3 from our website.