Hi,
There are really only 2 possibilities for this problem. Either nican.h does not have the read attribute set (and you are using NTFS), or the file is not in your path. It is more likely that it is not in your path. You should be able to put the nican.h file in the directory that has all of the code, and do a "#include "nican.h".
Hope this helps out.
Best Regards,
Aaron K.
Application Engineer
National Instruments