I just logged into Intel Business Portal, https://businessportal.intel.com/. The doucment search does not appear to be working, but the document does show up when you look at the list of available documents for the Intel(R) 82574 Gigabit Ethernet Controller.
On the documents tab I navigated by drilling down through Intel(R) Networking adn Communications Products --> Intel(R) Gigabit Ethernet Network Connection --> Intel 82574 Gigabit Ethernet Controller. That opened up a new browser tab with a list of technical documents in the Classified Design Information General Library. The OrCad files are the first item listed under Design Support - Other.
I hope this helps.
I will also let someone know that the search does not appear to be working. Hopefully, fixing the search will not take too long.