pc is part of another domain, but won't connect to home network

OK, I recently finished setting up my wireless home network for my dad, but for some reason my sister's laptop won't connect. It's set up on a domain at her school, and it used to connect ok, but now for some reason it just won't connect at all. The strange thing is though, In the wireless networks window it says that she's not connected but the button that should say connect is actually labelled disconnect- indicating that it IS in fact connected even though it isn't.

I'm using a DHCP server for the network, because static IP's won't work for some reason. I'm still refining the settings, I had to set up the router to be a non-dhcp server, and i'm using the dsl modem as the dhcp server.

 

How about some ipconfigs for starters? And maybe they equipment your setting up - router, ect..

 

Router: Linksys WRT54GP2
Modem: Linksys ADSL2MUE
Laptop: Toshiba Satellite L10

Modem is running DHCP, and is plugged into a network port on the router (not the internet port). Modem DHCP Server IP is 192.168.15.1, Router IP is 192.168.15.15 and isn't running a DHCP server, everything else is set to automatic.

I've been able to get my PC's wireless card set up using 802.11g, and my Mum's Laptop is also set up wirelessly using 802.11b. I think it may have something to do with her school setup, because I remember when I was at that school, the first time I plugged my laptop into their network a console window appeared onscreen (probably a batch file or something) and installed the network antivirus program and diabled a ton of networking features through the registry. I've been able to set up her laptop with all the details (encryption key, network name, etc..) required for her to connect to the network, but it just sits there saying "aquiring network address" and after a few minutes it decides it can't connect. I managed to get it connected using a static IP, but it can't use any network resources. Then after say 5 minutes it just disconnects.

 

then how about deleting tcp/ip and starting fresh?
Just reconfigure everything after reinstalling tcp/ip. This will probably delete the school's settings.

 

It's not the TCP/IP settings that aren't working, they were all set to automatic.

I think I may have to contact the school and find out from one of the network technicians how to reverse the damage they've done. I'm pretty sure it's something that's been changed in the registry, as I can't seem to modify any of the wireless network settings (can't change the order of school based networks, etc..) and I can't use any third party software to set up/change the wireless configuration.