The suggestion to go back and confirm that you have really installed NI-DAQ is a good one. Here are some other thoughts.
Are you loading an application you built in an older version of LabVIEW, and this is the first time you are loading it in 5.1.1? Do you still have the older version around? You should be able to go back to it and see where those VIs are found. The standard DAQ VIs don't have names like that. They're more like "AI Start.vi", not "aistart". But maybe older versions of LabVIEW used different names. If these are DAQ VIs from an older version of LabVIEW, you don't want to try to use them with a newer version of NI-DAQ. That'll almost certainly cause problems. You'll need to replace the old calls with the newer VIs. Let us know what you find out. Brian
