Does the NIC show up in the Device Manager - Hardware section?
Did you go into the BIOS and disable the on-board NIC interface? If not, the system may be getting conflicting hardware messages.
Do you have a friend or relative from whom you could borrow their NIC card and see if it works in your setup?
Which ever store you bought the Trendnet card from should be willing to take it back since your having issues with it. They may hit you with a 15% restocking fee though.
I know that D-Link, Netgear and Linksys make very good NIC cards. For the price Airlink101 NIC cards are pretty decent too. Linksys is not supporting some older cards these days though.
Great price on an Airlink card
here.
You're about 26 miles from a Fry's Electronics you could look there too. Here is some from their
website.