In reply to:
i cant use the setup disk as it cant find the modem.
Setup disk??? It's a router. As others have suggested, a factory reset is the next move, then using a known good ethernet cable pointing your web browser at the IP address of the router LAN interface. Make sure your pc is configured for dhcp - or fixed IP on the same subnet as the router factory default IP address.
=======================================
Everything below the line above is my sig
[Notice: Private mail is turned on, but anything received by these means can and will be published]