Home network problem

My main computer is a Dell 4700 with Win XP. I have a Linksys wireless router that it plugs into. I have another Dell 2400 with Win XP in another room that connect via the wireless router. It's worked fine for years. A couple of days ago I noticed a virus threat on the 2400. (It has AVG Free 8.5) I scanned it and it said it cleaned it up. I also scanned with Malewarebytes and with Superantispyware. They all found some stuff but all said it was clean. I also scanned with Trend Micro Housecall which found one trojan but cleaned it.

During this time I started to notice that although the computer said it was connected to the internet it wouldn't go to pages on the internet sometimes. Sometimes it worked and sometimes it didn't. It could get email though. I knew it had something to do with the viruses which was why I was running the scans. All the scans say they are clean now and it seems to be getting on the internet okay but when it's connected to the internet my main computer (4700) only has limited connectivity. It can usually get email and be connected to Windows Live but can't go to websites. If I turn the other computer off or disable the internet on the wireless computer my main computer has no internet problems whatsoever so the problem is definitely being caused by the wireless computer.

So, how can the second computer be interfering with the main computers internet connection? Thanks.

Paula

 

Resolved.