Hi,
The action to solve the problem you are getting will depend on the error message you are obtaining, look at this KB article that has a general guidelines to solve this kind of behavior :
http://ae.natinst.com/operations/ae/public.nsf/fca7838c4500dc10862567a100753500/be15fb343c2e9ba4862569dc007ac900?OpenDocument
Additioanally you can also look at the following documents:
http://ae.natinst.com/operations/ae/public.nsf/fca7838c4500dc10862567a100753500/87cd70c0749f34e186256a2c0058122f?OpenDocument
http://ae.natinst.com/operations/ae/public.nsf/fca7838c4500dc10862567a100753500/bb10d4bb7de506ab862569dc006a61a7?OpenDocument
http://ae.natinst.com/operations/ae/public.nsf/fca7838c4500dc10862567a100753500/3ac05da158ea6fb7862569dc00684a34?OpenDocument
Best Regards
Andre Oliveira
Applications Engineer
National Instruments