Internet router not working for Windows XP

I have two computers, both running on Windows XP. I have a cable modem, which is running into <A href=http://www.netgear.com/products/details/FS605.php>this router</A>. When plugged into the router, one computer works and the other one doesn't.
I currently can get one computer to work on the router at a time, but never both at the same time. This router has worked in the past on two computers. Anybody know what the problem is? Am I supposed to set up a LAN? I don't remember having to do that in the past.

 

I've had to deal with router problems before on home networks (I actually called technical support once ) What they will tell you on the phone is to fully reset the router and modem, and they should automatically resolve each other and work. I assume this is how your internet connection is setup cause you said you have a cable modem (compared to DSL which uses a different method of connecting to the isp).

I checked out your router. it's actually a switch. did you link the right product?

 

It's the right product, I was just calling it the wrong thing.

In the past I've been able to go online simmultaniously with 2 seperate computers on this switch, though.

When I turn off the computer and unplug the modem and turn on the computer only that computer works and the other one which was online already stops working.