XP SP2: uh, what happened to my connectivity?

Since I keep my Windows machine up to date and I have finally been notified that SP2 was available I decided to upgrade. But after an apparently successful installation and reboot and curious set of intermediate screens I discover that I cannot use either IE or Firefox to browse the web. I'm going to keep a little running diary of what I need to do, or learn, or fix, or ..., to get back to the fully working configuration I had a few hours ago. (I'm adding this to a new category named "user experience.")

1. Upgrade actually started on Friday, 10 Sept when I brought up Windows update and downloaded and started the install. I didn't hang around to watch all 90+MB to download, and when I got back I saw that the install failed, but there wasn't any reason given. I was logged on as a normal user, but I did run the update as an admin. That was Friday, a nice weekend intervened.

2. Today I decided to log on as the admin and run the update; maybe better luck?

3. As far as I can tell I have network connectivity locally. I can ping and connect to other computers on the home network, but cannot get out.

4. nslookup is working and uses my ISP's name server to resolve addresses. It's just that the browsers don't work.

I'm kinda peeved by this since all the previous XP upgrades have been applied with no interruption in my systems capabilities.

I know that this one comes with its own firewall. But I have a firewall, so I turned that off. That might be mistake number 1.

5. I did think that maybe I need to do network setup again, so I tried to use the Network setup wizard to configure a connection to the local LAN. The wizard says all is OK, but the browsers don't work.

6. DIYIT: I'm agree with Stuart Henshall, I don't want to be doing this. I want to be using the computers.

More to come ...