Acquiring Network Address; but works perfectly on all other networks

Hey, thanks in advanced for answering my question.

I'm working on a friends laptop that used to connect wirelessly to their network no problem, and all of a sudden it would no longer connect at all. It a 5 year old Gateway laptop running Windows XP Media Center. It just hangs at "Acquiring network access" and never connects. I'm pretty sure it's their network because it works on my home network perfectly, connects and stays connected.

Can you give me some pointers to do to the laptop and/or the network? I normally would start fresh with the wireless network, but they have a bundle package of AT&T (internet, phone & TV all-in-one) so the router is branded AT&T and don't want to mess any of that up. Should I advise them to go to AT&T for help or will they even help with that?

Please let me know what I can do, I would really appreciate it.

If the connection is falling over at the handshake stage, it may be a channel problem. Try configuring the laptop's wireless device to receive on the same channel as one of the other machines in the system - or set it to automatic so it searches for signal from any channels?

It's also worth trying to connect it to another network outside its usual environment to prove all the relevant settings are correct.

Thanks for both of your replies. I'm going to tell them to contact AT&T first to see if there is anything they can do (although I doubt they'll even care) to correct or diagnose the problem.

I will post what happens here. Please let me know if anyone else has any suggestions, I'd appreciate it!