The original rhn-applet included in Fedora Core 1 does not detect available updates properly. To fix this issue: 1. Download the latest rhn-applet rpm package. rhn-applet-2.1.4-3.i386.rpm 2. Install it with following command. # rpm -Uvh rhn-applet-2.1.4-3.i386.rpm 3. Log out and log back in. 4. Right click on rhn-applet and choose 'Check for updates' 5. If it becomes red, right click on rhn-applet and choose 'Launch up2date..." See TUTORIAL: up2date for more information.