<<< The desktop shows two connections Lan + Lan 2, lan 1 is connected to the router via ethernet & lan 2 is connect to the modem (adsl ntl)is it correct that both Lan's have different ip addresses if so which one should i connect to? >>>
The WRT54GS router's WAN port should be connected to the NTL Cable Modem via ethernet. The computers then both connect to the router, either "wirelessly" or or by ethernet cable. If you have NTL's ADSL service delivered via the phone line, then you have the wrong router.
There should be no direct connection between a PC and the modem, it is the router's function to connect to the ISP and deliver internet access over the LAN to the networked computers.