LAN works, but no Internet Access

As the title says, my computer currently has local LAN access but it cannot access the Internet at all. This computer use to access the Internet just fine. The problem started about 1 month ago. First let me sat that this computer is running W2K with Norton Internet Security 2005 and Norton AntiVirus 2005.

About a month ago, I was updating NIS/NAV and the computer locked up during the installation of the updates. I rebooted the computer and it seemed to work ok for a couple of days. Then the problem started that I could access my local LAN but I could not access the Internet. So I disabled NIS, and then I was able to access the Internet. I finally decided to uninstall and reinstall NIS/NAV, so that I would not have to disable NIS in order to access the Internet. Well I did this and now I cannot access the Internet at all.

Currently, NIS/NAV is uninstalled. Any suggestions on what the problem might be? Should I uninstall and reinstall Internet Explorer? Is there some system file that might be corrupted?

Thanks,

have you tried reinstalling Norton just to see if it can fix any corrupted files. It maybe that a component of the firewall has not been uninstalled because of the failed update. Check the protocols/services bound to the network adapter to see if there is a firewall component still active