Hello, I have a peculiar problem with my exchange 2000 that it restarts after few hours from its launch. I have copied the events id below for your analysis and help me to stop this issue. I had Trend micro antivirus software installed before and now I have uninstalled but still the problem persists. It starts with the Event Id 1000 and goes up to event id 9154 and repeats the sequence for 5 times and restarts. I would appreciate your help. Thanks, Suresh Event Type: Information Event Source: MSExchangeSA Event Category: Monitoring Event ID: 9096 Date: 03/06/2005 Time: 18:11:02 User: N/A Computer: MAILSERVER Description: The MAD Monitoring thread is initialized. Event Type: Information Event Source: MSExchangeSA Event Category: Monitoring Event ID: 9095 Date: 03/06/2005 Time: 18:11:02 User: N/A Computer: MAILSERVER Description: The MAD Monitoring thread is initializing. Event Type: Error Event Source: MSExchangeSA Event Category: General Event ID: 9154 Date: 03/06/2005 Time: 18:10:31 User: N/A Computer: MAILSERVER Description: DSACCESS returned an error '0x80004005' on DS notification. Microsoft Exchange System Attendant will re-set DS notification later. Event Type: Error Event Source: MSExchangeDSAccess Event Category: Topology Event ID: 2102 Date: 03/06/2005 Time: 18:07:29 User: N/A Computer: MAILSERVER Description: Process MAD.EXE (PID=1556). All Domain Controller Servers in use are not responding: server1.pod.co.ae MAILSERVER.pod.co.ae Event Type: Error Event Source: Userenv Event Category: None Event ID: 1000 Date: 03/06/2005 Time: 18:07:15 User: NT AUTHORITY\SYSTEM Computer: MAILSERVER Description: Windows cannot query for the list of Group Policy objects . A message that describes the reason for this was previously logged by this policy engine. Event Type: Error Event Source: Userenv Event Category: None Event ID: 1000 Date: 03/06/2005 Time: 18:07:15 User: NT AUTHORITY\SYSTEM Computer: MAILSERVER Description: Windows cannot establish a connection to pod.co.ae with (1364).