Broke yum when upgrading from FC4 to FC5
 

I upgraded from FC4 to FC5 using CDs I'd burnt. Everything went well with the installation, and all the data previously there was preserved. The only problem is that yum still looks to the FC4 repositories for updates, and gives me a "failure" message saying that it has tried all the mirrors and cannot find anything for FC5. How do I remove the current settings, and do a clean install of yum?

Had you edited /etc/yum.conf at any point before the upgrade? If so check to see it /etc/yum.conf.rpmnew exists and copy that to /etc/yum.conf. You can also reinstall the fedora-release rpm for FC5.

I had edited /etc/yum.conf before the upgrade, by getting it to point at the fedorafaq site. I reinstalled it from the CD as I only had an /etc/yum.conf.bak file (not the original file) and checked it against the /etc/yum.conf.rpmnew file. The two appear to be identical. It still won't update. What is the next step - deleting all yum files and using up2date to reinstall it?

Did you install the fedora-release rpm for FC5?