I am facing certificate error on all client workstation. Things were working fine but with recent changes there was a problem with OWA accessibility. I had replaced the modem and router. I had also changed the external and internal SBS NIC and then configured settings commonly on all the system but it looks not to be working fine. I had manually changes all the settings so it must accept it and it should work properly. But somehow there is trouble with using the same. Does anyone has any idea how can restore the old settings.