After changing the Global Administrator password in AD, the Event Parser service stopped and would not restart. The logon account for this service is LocalSystem. Does this password change need to be updated in another configuration file? Changing the password back to what it was enabled the service to start.
I'm guessing that this account is also used by ePO to access SQL. If so, then you'll need to enter the new password in the SQL config page (<eposerver>:8443/core/config by default)