I'm not 100% sure what you're asking. But I think you're saying you've set up a wireless network that you cannot connect to since you don't have a wireless card. And now you want to get rid of it. Correct?
If that is the case:
Open Control Panel -> Network and Internet -> Network and Sharing Center.
On the left side you'll see "Manage Wireless Networks"
You should be able to click whatever is there and say remove. (if that's what you wanted)
I think that was it. although after I removed it it still did not work.
I ended up just giving my lan an ip address, 192.168.1.xxx in the range that my router assigns. Gateway, 192.168.1.1, dns 192.168.1.1 and 192.168.1.0. Since my router is a client bridge it worked, DD-WRT.
Saw this method posted elsewhere and it worked, not the most elegant solution but I am online now. I'd rather have it set so that an ip and stuff is auto assigned by my router, but this works fow now.