Networking/Browser Problem.

I have set up a LAN at home using a router and four pc’s(all running windows 98). All four can see each other, share folders, etc. However, only three can surf the web. The fourth can ping,, etc., but can never find the server when opening the browser. I’ve downloaded netscape and IE but neither worked. I’m starting to think the problem is in the registry but I have no idea what to look for… My last resort will be to format the hard drive, but I’d really like to try everything before it comes to that.