Hi, I am looking after a 2008 server at a school. I am getting errors regarding certificate expiration, so I looked and found in Local Computer/Personal/Certificates that the Client Authentication certificate has expired. This server is the GC and AD – only one in the domain. Should I install Certification Services in Roles to fix this? I can’t auto enrol and there is no higher authority. This DC has no direct connection to the world. The only thing that concerns me about installing the Cert role is the warning about not being able to change the name of the server (won’t ever want to) but “domain settings” concerned me because were are about to change IP range. Don’t want to do anything hasty but how will this affect logins if I do not renew? Thanks for your time – it’s much appreciated.