- Can you tell more about "does not work". What happens (like error messages) if you do what? Can you ping the router, to name an example?
- Did you use the cd that came with the router on this computer when you installed the wireless communication the first time? Then repeat it. Else it isn't necessary, I should say.
- Are you sure you installed everything that had to be installed? Is it PCI or USB (you write Ethernet, which is very well possible indeed)? If Ethernet or USB on the motherboard: did you install all the motherboard drivers? Windows XP doesn't do it for you. And you don't really tell what was on the "cd's that came with the computer".
- Assuming it's connected to an Ethernet NIC, and your husband uses Ethernet also, can you make a Direct Cable Connection to his PC (use a cross cable) and 'see' each other? If so, the Ethernet works, and the problem is in the wireless indeed. Else, it's doubtful where the error is.
- Can you connect wired from the NIC (use your husbands cable)?
- Are you sure you followed the correct installation instructions? Does the troubleshooting section of the Linksys manual help in any way?
- Any problems in Device Manager?

Just some thoughts. Not a real solution, I'm afraid.