2000/XP Socket failed to initialize

I'm having a problem with TCP on a computer. It started when a
wireless PCMCIA network card was added and then removed. Everything at
the IP level works. I can ping and do traceroutes with any problems.
Netbios/Netbeui stuff works. I can see and access windows shared
drives from other computers. But anything else that uses sockets
doesn't work. Some apps pop up the message in the subject above. Some
just timeout.

I've looked through the registry and looked for missing dlls and
didn't see anything wrong. I deleted and reinstalled the network card
(built in ethernet port) and networking stuff. I even, as a last
resort, upgraded it from 2000 to XP all to no avail. There are a bunch
of messages in event log from applications and services which failed
because they can't access the network but the only thing I see related
to the network stack itself is something about snmp being successfully
shut down. Why this is happening I don't have a clue.

Any advice or hints on what to look at would be greatly appreciated.

Hardware:
Dell Latitude L400