yum configuration question

[Vicki Stanfield]

Having been away from Red Hat for a bit, I find myself
ill-equipped to answer what is probably a relatively simple
question. I have installed Fedora Core release 4.90 (Pre-FC5), and
IIRC yum worked initially. When I try to use yum now, however, I
get an error which based on my googling seems to be a
misconfiguration of yum. I didn't remember touching yum, but this
machine is set up as a reference/play machine, so I can't say
definitely that I didn't do a yum update or something that might
have changed the config.

I run:
  yum update
and see the following:

Loading "installonlyn" plugin
Setting up Update Process
Setting up repositories
Cannot find a valid baseurl for repo: updates-released
Error: Cannot find a valid baseurl for repo: updates-released

I can go and disable the file that starts with updates-released to
get rid of the message, but that prevents me from accessing any of
the updates; doesn't it? If anyone can tell me what yum config
files I need to just do normal updates and installs (no bleeding
edge required) and what repos should be listed in the repo files,
I can get back to being able to yum. Incidently the
updates-released line is in the fedora-updates.repo file, so that
might be the only one broken. Maybe I should check which are
enabled, so knowing which are supposed to be enabled would be a
help as well. Thanks.

Vicki