Fresh XP install-->>no automatic updates

[David]

I recently reinstalled XP Home over a corrupted/failed XP
Pro setup.

Following install, I've been unable to automatically
update "anything"...
-XP updates show updates I need then says update "failed"
-Norton Antivirus shows "failed" or error LU1803
-Encarta won't update

I CAN download individual security updates (like the
blaster one) and don't have the virus.

Appreciate any help, thanks
David