I setup a Linksys range extender model # wre54g on my home network. All the laptops in the house connect to it, no problem with full signal. When I try and connect my Xbox 360 it tells me there are multiple networks and wont connect. I think its getting confused with the router and ranger extender both sending out a signal. Any ideas on how to fix this?

I haven't messed with a range extender in a long time. Do they have IPs themselves?

If so, you can manually tell the Xbox that the Default Gateway is the range extender and the DNS is your router.