Wireless on Windows NT

I have an old computer with two network cards (one was an internal card that got fried and a second we installed to replace that). Now we’re trying to use a wireless to connect.

(For those curious, we moved the computer upstairs and didn’t want to drill holes through the floor)

The problem? The computer insists I have a private address and my only other alternative is to give it a user configured IP address.

And regardless, setting it doesn’t seem to help. Is it possible that the other network cards are interfering?