Hi, i am trying to install Exchange 2007 on a Windows 2003 R2 domain controller (with all current updates) after installation, my DC crashed constantly with following error messages "lsass terminated unexpectedly" -1073741819 "The security package Kerberos generated an exception" If i disable Exchange Information store and other exchange services, the machines starts normally... In the Application event log, Exchange complains that it can't contact a domain controller, Any help is appreciated Thanks