Windows 7 recognizing wireless network as VPN/Dial-up

My roommate got a new computer, which includes a firewire modem, and Windows 7. Windows 7 seems to be recognizing our wireless network as a Dial-up/VPN, and tries to connect to it through the firewire modem.

To solve this problem, I hard-wired the wireless network to his computer via an ether-net cable. It recognized the connection as a "public network" and allowed him to connect to the internet, so we let it rest.

Suddenly, after I moved my room around (but plugged all the hardware into the same ports across the board) his computer no longer recognizes any kind of ether-net connection.

So my question has two parts:

How can we get Windows 7 to recognize our wireless network as such?

If you have an answer for this first question, ignore the second. If not:

Why is his computer suddenly unable to recognize the land-line that worked just a few days ago?

I asked him if he installed anything new, or screwed with any settings, and he says no... I don't believe him. His last computer was rife with viruses and malware.