I searched around, but didn't find anything exactly like this:

I have a Thompson DSL modem, but it has a router built into it (4 port - yes, the router and modem are all-in-one). I need wireless in my office, so I have a Network Everywhere (Linksys) 4 port wireless router, but I can't get it to work with the modem... I guess because they are both routers, and not switches.

The internet works on all computers hooked to the modem, but no internet on anything (wireless or not) on the wireless router.

How can I configure these two devices to work together?

Thanks for your help.

You need to configure the Linksys to:

1) Use a different IP on your WAN than the Thompson - by default both are probably trying to use 192.168.1.1.
2) Use the Thompson's IP as it's "default gateway".
3) Either disable DHCP, or set it to use a different subnet.

WOW! That did it instantly. I knew it couldn't have been too complicated, but it was just barely out of the realm of my knowledge. THANK YOU SO MUCH!