Internet connection not working through router

[solar_powered]

I'm having trouble getting a computer to connect to the Internet through a router.

We had two computers that were networked via a Linksys ethernet router.  The modem and both computers were plugged into the router, and both had Internet access without any problems.  We just bought a new computer and a wireless router with the intention of getting rid of the old router and setting up a combination wired/wireless network.

I'm not sure what I did, but now the Internet connection doesn't work through either router (the old cable one that used to work fine, and the new wireless one).  It didn't work at all until I called the ISP tech support and fixed the set IP address, but now it only works when plugged directly into one of the two older computers.

The modem is fine; the router does recognize the Internet connection and the computer that's plugged into it.

To set up the wireless part of the network, I need to be able to configure the router, but that means I need a computer with both Internet access and a connection to the router.  So until I can get the computer to recognize an Internet connection through the router, I'm stuck.

Computer that has Internet access when plugged directly into the modem: Dell Dimension 4300 with Windows XP
New computer: Dell Dimension E510, also with Windows XP
ISP: Earthlink
Old cable router: Linksys EtherFast Cable/DSL Router model no. BEFSR41 ver. 3
New wireless router: Netgear 54 Mbps Wireless Router WGR614 v6

Please help?

[Backdated]

This router should more or less set itself up.
If you're running XP, is the UPnP service running?
It's good practice to always have your main computer wired to the router. That way, you always have control. Hard wire computer 1 to the router and get that up and running first. Worry about the wireless setup later.

Set up the TCP/IP properties for your NIC using 192.168.0.1 for gateway and DNS for now. Set an IP of 192.168.0.3

Once wired, open the router control panel, usually by pointing your browser at http://192.168.0.1
At this point, decide whether you want to use static IPs on your LAN. If no machines are constantly leaving and joining the network, static IPs are good practice and much easier to troubleshoot.

Once decided on whether you want to use static IPs or DHCP, post back.

[solar_powered]

I tried that, but the Internet still doesn't work when it's connected to the router.  I can access the Internet through a direct connection and through the old router now, though, so I'm back where I started.  I'm looking at the Netgear tech support page and there are a few things I'll have to try when I have time.  I'll come back here if none of that does anything.  Thanks!

[solar_powered]

Okay...I plugged it in again and this time I actually got to the router configuration page (but it was at 192.168.1.1).  I set up the wireless connection, and the new computer recognizes the wireless access point.

But neither one has any internet beyond the router control panel.  The computer that's wired to the router says that the LAN is connected and functioning, but it's not functioning.  Actually, right now, the modem isn't plugged into the router or that computer, so I have no idea why it still says it's connected.

The computer that's wirelessly connected to the router says, "You are connected to the access point, but the Internet cannot be found."