TalkTalk Wireless Router - HELP

OK I’m not normally one to ask questions concerning Routers and Networking as I’m normally pretty hot on how to solve issues etc.

The problem is, my neighbour has asked me to help set up the Wireless Router supplied from TalkTalk. He is using a laptop primarily to setup the router using the Ethernet cable and then be able to leave the router unattached to a computer. First time around we had problems due to the actual router not being shown on the CD. An hour later another CD is produced and it turns out thats the one we need to use.

Regardless of this, once the Router was connected via the Red Ethernet cable, it was showing traffic, but after a minute or so it would say that there was limitted/no connectivity.

Used this other CD to try and install and it has the right image of the router etc. However, (again) it goes to check the connectivity to the modem and again it fails. It tries to renew the IP address to no avail, it just hangs.

Has anyone else had this problem with TalkTalk?

The model is the Huawei Wireless HG520 as shown on their site. He is using Windows XP which is odd, as the guide online only shows for Vista/Macs but appears to work fine on his Machine until the said check for connectivity with the modem.

Any help on this would be greatly appreciated.