Windows 7 Shows my wireless network but I can't connect

Background:

I recently build a Frankenstein desktop, or at least that's what I'm calling.

I started out replacing the motherboard in a HP Pavillion p6130y desktop.

After some research I found that the stock motherboard as pretty outdated so I decided to go aftermarket.

I wanted to replace as little as possible but now the only original parts are the dvd drive and network card.

The network card has to screws on the back to attach an antenna and is a PCI1x card.

Current Problem:

I now have a problem where after installing the card and Windows 7 Professional , I can see the list of available wireless networks including my own.

But, I cannot connect to any of them even though my own network has full signal strength.

Any help is appreciated, this is my first experience with Windows 7 and this is driving me crazy.