Got a spare hard drive? Try doing a quick install of win98se or somesuch, to see if it can then load the drivers properly.
Or is your problem that the Local Area Connection appears fine in the Network Connections screen, and the LAN adapter looks fine on the Device manager screen, but IE can not bring up web pages? If this is the case, open a command prompt window, and try pinging your ISP's DNS server. If that works, the problem is that your networking components have gotten screwed up. I've seen this happen on various boxes, in fact it happened to mine yesterday! All you need to do is go into Add/Remove Programs, click the Add/Remove Windows Components button, and remove the networking. Reboot with the LAN port disabled in the bios, then reboot again, re-enabling the LAN port. Winblows should load the drivers automatically (or you can load them manually if it does not), and you should then be able to get back on the net.