Kevin,
A lot of software isn't on the web after it falls out of the support cycle but you can sometimes get it by registering the product to your MyNI account and then searching ni.com/downloads.
If you can't find it after doing that I would suggest calling in to NI. When you call in just make sure you have your serial number for the product. You should just need to tell the person you are talking with what you have done to try and download the software and why you need it.
Matt J | National Instruments | CLA