HELP- I think my home network was attacked

I have a ATT DSL connection and modem and have a Linksys Wireless WRT54G router.
About 1.5 -2 weeks ago my wifes desktop HP computer that is wired to the router started having problems with IE not being able to connect to the internet (I found this out afterwards of course)
So the wife just started to use Firefox and had no problems getting online and accessing the internet until about 2 days ago and then Firefox was not able to access any web pages.

During this time my desktop HP computer that is in the other room that connects wireless to the router had no problems with either IE or Firefox in connecting the internet and viewing web pages...that is of course until 2 days ago when the wife was not able to connect at all.

I called ATT DSL and checked out the connection and modem and it's OK and went through reseting the Linksys modem and everything works BUT I had to do it with my laptop which was NOT connected to the network at the time these other problems started to happen.

My wifes computer shows it is connected to the network but the NVIDIA nForce network card does seem to be working and I can't get it to connect.
Norton keeps popping up a dialogue window that reads.."no such Interface Supported", with a 10,99 number in the bottom left side of the window with an OK button...and then after a couple of minutes the computer restarts and this goes on FOREVER. How do I stop this? We use these computers to make a living and this is a big problem.

Also my wireless desktop cannot connect. It won't show the wireless networks as it usually does, and when I try to repair the wireless connection it fails

Do we have a virus? Worm? Trojan?

Your help is greatly appreciated

Thanks in advance

 

Hi,

Until someone more knowledgeable then myself can help you, do you have a spare network card to try in her computer just to rule out a hardware issue?