Internet connection

My friend who has the Linksys1 wireless broadband router hooked up although she's not using it with her Gateway desktop. We're trying to see if we can use her Dell Inspiron 2500 wirelessly. Gets an error message. So we have it plugged in, and it's getting power, but when I go to Internet Explorer get the "page cannot be displayed" screen. I've heard there are ways to search for the wireless service, but would be happy just with the internet connection.
I have the add/remove program screen up, and see that it shows Netgear and "2 wire wireless client" (not sure what that means.
Any suggestions.
Final question, on the gateway desktop keyboard, which only she uses, and from which I'm typing I notice that I'm typing but nothing is showing up on the screen. Would you know why.