We found this:
See if a registry key that exceeds 259 characters exists in the
HKEY_CLASSES_ROOT registry hive
The "503 Service Unavailable" error message may occur if a registry key that
exceeds 259 characters exists in the HKEY_CLASSES_ROOT registry hive. During
initialization, the Exchange OLE DB provider (ExOLEDB) scans the
HKEY_CLASSES_ROOT hive to identify registered file types. If any subkey has a
default value that exceeds 259 characters, or if there is a discretionary
access control list that is not valid on one of the subkeys, ExOLEDB may quit
unexpectedly.
If a subkey exceeds 259 characters, or if there is a discretionary access
control list that is not valid, the following series of event ID messages are
logged in the application event log when you restart the Exchange 2003
services:
Event Type: Information
Event Source: MSExchangeSA
Event Category: General
Event ID: 9014
Description:
Microsoft Exchange System Attendant has been started for Exchange server
servername successfully.
Event Type: Information
Event Source: MSExchangeSA
Event Category: Monitoring
Event ID: 9095
Description:
The MAD Monitoring thread is initializing.
Event Type: Information
Event Source: MSExchangeSA
Event Category: Monitoring
Event ID: 9096
Description:
The MAD Monitoring thread is initialized.
Event Type: Information
Event Source: EXOLEDB
Event ID: 101
Description:
Microsoft Exchange OLEDB has successfully shutdown.
Event Type: Error
Event Source: MSExchangeIS
Event ID: 9542
Description:
Initialization of external interface OLEDB failed; Error ecServerOOM.
Additionally, the following event ID message may be logged in the
application event log multiple times. The Free/Busy service may also generate
some errors.
Event Type: Error
Event Source: EXCDO
Event Category: General
Event ID: 8206
Description:
Calendaring agent failed with error code 0x800XXXXX while saving appointment.
The following event ID message may be logged in the system log multiple times:
Event Type: Error
Event Source: DCOM
Event Category: None
Event ID: 10002
Description:
Access denied attempting to launch a DCOM Server. The server is:
{9DA0E106-86CE-11D1-8699-00C04FB98036} The user is SYSTEM/NT AUTHORITY,
SID=S-1-5-18
To help troubleshoot this issue, run the HKCRScan tool (HKCRScan.exe). The
HKCRScan tool enumerates the HKEY_CLASSES_ROOT registry hive to locate
subkeys that contain more than 259 characters. Additionally, HKCRScan helps
determine if there is an invalid discretionary access control list by
returning error code 0x5. This error code means "Access denied" when it
enumerates a registry key. The HKCRScan tool is an internal tool developed by
Microsoft. To obtain this tool, contact Microsoft Product Support Services
(PSS). For additional information about how to contact PSS, visit the
following Microsoft Web site:
"FerrisUML" wrote:
> Hello all and thanks in advance for any advice anyone can give.
>
> Problem im having is that randomly, users will call and say that their
> icons an such are missing and their Outlook is not setup. Well, after
> examing closer, whats happening is Windows is completely overlooking
> the original user profile and creating a new one with the syntax
> "username.domain_name". I check the Event Log, but there no
> information on a corrupt profile/registry at all. Anyone have any idea
> what may be causing this to happen? Thanks.
>
> FYI
> We're a 2000 domain with a mix of 2000/XP clients and I don't think
> this problem is isolated to just 2000.
>
> >> Stay informed about: Win2000 creating new user profile while old still exists