He could have setup MAC filtering so that only his computer can get on the wireless. Otherwise, it will block anyone else who tries to get online. MAC address of course is a label on your network access device (LAN Card or Wireless Card) that is similar to an address of a house. In the big picture, when the information is routing from the source to the destination, it needs to know what computer it should deliver the packets of information to. So by enabling this section in the router, it will allow him to only "receive and send information" while all others will be denied.
Hope this helps!
So, i've got a Linksys Wireless Router and i've always been able to connect to it with some few exceptions where I was required to reset my modem and such. My brother who's pretty distant from the router gets 2-3 bars and he's been looking for a way to fix that so he's been going into the wireless router changing the frequencys and who knows what else. God forbid he tells me. So, this morning as I was going to check my emails, the little computer figure on the bottom right showed a yellow sign with a ! in the middle. I put my pointer over it and it showed that I had "Access: Local Only". Usually it says "Access: Internet and Local" and those times I would be able to connect. Anyways, so I thought that I should reset my router and I did and once again I got "Access: Local Only". So, I went and asked my brother if he was able to connect, and he was, but with 3 bars. I tried my dad's laptop which is near mine, and I couldn't connect on that either so it seems that only my brothers computer can connect to our wireless network.
I asked him what he had done, and his stupid answer was "nothing" which is complete bs since he's always inside screwing with the router settings so he can get more bars. So, at the moment i'm connect to "default" on wireless network. I'm using Vista for my OS. I'd really appreciate it if anyone can help. Sorry for the long thread. Just wanted to give you all the main story incase it helps in any way.