Are you trying to install this from a cd or did you download the file from our website?
If it is from a cd, I would recommend copy the contents of your cd to your hard drive and then installing it from there.
If it is from our website, I would try to download it again, or try the
installation on a nother computer. It is possible that the file
somehow became corrupted when you were trying to download it.
Just out of curiosity, are you installing NI-DAQ 7.4 Traditional? If you want the newest version of NI-DAQmx, it is version 7.5!