RHEL -> CentOS
AutoUpdates in RHEL 5 will be voided after Redhat Linux Enterprise subscription expired .
I have tested below script to change a 32bit RHEL’s yum repositories back to use those from CentOS , and yum update works fine:
Reference : http://www.techexams.net/forums/off-topic/50016-how-convert-rhel-centos.html