Hi Allen, <a href="http://digital.ni.com/public.nsf/websearch/838170FB4A3EA0FB862561C60065C2F7?OpenDocument";>Here</a> is a link that talks a little bit more about Error 21. If I understand your problem correctly, I would lean towards making sure that you have all of your DLLs on the target machine and that they are located in an accessible directory. Good Luck!
Jeremy L. National Instruments
