I have just installed (what I think you mean a Belkin) ADSL modem with wireless G router. I encountered the same problem. The reason this comes up is that in your network setings, your IPs for both computers have been set as the same. Therefore they are clashing.

This is how you fix it (I assume you are running Windows XP):

You will need to do this for ALL computers on your network

In order for your computer to properly communicate with your Router, you will need to change your computer?s ?TCP/IP Ethernet? settings to ?Obtain an IP address automatically/Using DHCP?. This is normally the default setting in most home computers.

You can set up the computer that is connected to the ADSL modem FIRST using these steps. You can also use these steps to add computers to your Router after the Router has been set up to connect to the Internet.

Manually Configuring Network Adapters in Windows XP, 2000, or NT

1. Click ?Start?, ?Settings?, then ?Control Panel?.

2. Double-click on the ?Network and dial-up connections? icon
(Windows 2000) or the ?Network? icon (Windows XP).

3. Right-click on the ?Local Area Connection? associated with your
network adapter and select ?Properties? from the drop-down menu.

4. In the ?Local Area Connection Properties? window, click ?Internet
Protocol (TCP/IP)? and click the ?Properties? button.

5. If ?Use the following IP address? (2) is selected, your Router will need to
be set up for a static IP connection type. You will need to enter this information into the Router.

6. If not already selected, select ?Obtain an IP address automatically?
(1) and ?Obtain DNS server address automatically? (3). Click ?OK?.

Your network adapter(s) are now configured for use with the Router.

I hope this helps. The above is extracted from the Abobe manual on the installation disk.

Good Luck for the future.

Gaz