Windows XP sign on problems

[HotWire]

All of a sudden two of my computers stopped accessing the internet and both are running Xp...1 home version and 1 Pro version they are connected to a router (linksys) as well as two computers running windows 98. the Computers running 98 sign on just fine via my cable modem system but the two with XP on them are both down and out and it looks like they both stopped on the same day which tells me it could be some type of network setting I changed recently, perhaps when trying to network the two togeather......anyway microsofts support line didn't help me out after about an hour of trying....but my file/case is still open for a return call. They appear to have the right tcp/ip settings so I'm stumped??? if anyone has had a similar experience and can shed some light on this problem you are welcomed to help.