I bought a laptop a few weeks ago with wireless built in (centrino) and have been able to pick up other networks in my apartment building... until last night. My roommate installed some applications to work from home and now my laptop won't connect to the other networks. what's wrong? when I ask windows to repair it, it says it failed to change my IP address..

He may have secured his/her network to prevent tresspassers from stealing signal. Ask you friend if they have change the settings. I'm sure your friend will allow you to link up. The other network is your friend's, right?