Problems with connection stalling/freezing...help

[JkiD2k2]

I have posted a few times about this but still haven't found any help at all after all the searching. So I decided to try and post in this forum to see if anyone has anything to help me out. First of all everything was working great and we had 3 computer connect to our router and our DSL service. Then our house got stuck by lightning and we had to replace the router, and get 3 new network cards. So now the internet works again but there is a problem with mine and my brothers computer. (not sure about the other one since it doesn't get used much) But we used to be able to stay connected to (for example) AOL Instant Messenger for around 3 or 4 days without getting kicked off of it. Now, I can only stay on for like 5 minutes IF THAT, without getting kicked off and reconnected. And also now, sometime when I'm downloading a file through IE it will stall at a certain percentage and just stay there until I restart the download. So something is wrong somewhere. Anyone have any ideas what it might be? We got the same brand router (LinkSys) but this one is actually a wireless one but we don't have it hooked up to use it as wireless. Can anyone think of any settings to try out or ANYTHING to try and configure it right if it even is that? Someone said it might be because its look for a DNS number or sever or something and thats whats making it do it... no idea what that means though. Any questions feel free to ask! Thanks in advance...