Okay so the problem is your network... Specifically the connection from the pc to your router. Have you got other computers on the network ? do they connect ok?
Another thing thats crossed my mind is your router's settings? Do you have a firewall enabled on the router? And does it filter mac addresses or limit IP addresses that can connect to it?
Does vista's networking stuff say it's connected? and can you connect to alternate networks?
Just trying to narrow down the problem, but if you can then check your router's settings because they could play a big part in it (i had problems setting up my router's firewall ages back and it frustrated me [A lot])...
If theres a mod around and they could move this to the networking forums it may get 1nikki180 an answer...
[Thread moved to Networking, thanks Jamey]
Cheers,
Jamey