So my Windows based Vmware Vcenter Server went belly up again. Something to do with the SSO database not starting. Not being a lover of Windows I decided to give the Vcenter Server Appliance a shot. Install was great and I am kicking myself a bit as to why I spent so much time fighting with Windows. My new Vcenter Server, which has a different IP address then the original Windows box (might make a great Veeam server) was not registered with Vcenter Operations Manager. I was not prepared to reinstall that thing again. So I needed to figure out how to manually unregister a Vcenter instance and add register another one in its place.