In Windows 2000, the Event Log service may stop logging events before the
size that is specified in the Maximum log size
reached if the Do not overwrite events
option is turned on.
This can cause events to be lost.
The event log generally stops logging new
events when the log reaches a size of from approximately 200 megabytes (MB) to
The Event Log service may report that the event log is full
and stop logging events before the maximum log size is reached. If the "Shut
down system immediately if unable to log security audits" Group Policy setting
is in use on a computer, the computer may stop auditing events and may stop
responding (hang) sooner than expected.
Service pack information
To resolve this problem, obtain the latest service pack for Windows 2000. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
How to obtain the latest Windows
A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem.
If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, submit a request to Microsoft Customer Service and Support to obtain the hotfix. Note
If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note
The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.The English
version of this hotfix has the file attributes (or later) that are listed in
the following table. The dates and times for these files are listed in
coordinated universal time (UTC). When you view the file information, it is
converted to local time. To find the difference between UTC and local time, use
the Time Zone
tab in the Date and Time tool in Control
Date Time Version Size File name
02-May-2002 14:28 5.00.2195.5722 45,328 Eventlog.dll
With this fix installed, you can
implement an automatic backup process (by using a registry key) when the
current event log cannot be extended. You can add a registry key for each event
log to increase the time before the event log becomes full, or before the
computer hangs. Note that the size of the event logs is still limited by the
available resources on the computer (such as virtual memory and free disk
has confirmed that this is a problem in the Microsoft products that are listed
in the "Applies to" section. This problem was first corrected in Microsoft Windows 2000 Service Pack 4.
This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:
How to back up and restore the registry in Windows
To use the new automated backup behavior after
you apply this hotfix, you must add registry keys such as the following keys:
Data value: Value not present or 0 (zero) equals "disabled."
(This is the default.) Any non-zero value equals "enabled."
You must restart the computer or clear the corresponding event
log before the new behavior takes effect. You must configure the event log to have the Do not overwrite events (clear log manually)
If you are using the "Shut down
system immediately if unable to log security audits" (CrashOnAuditFail) policy
and if you do not clear the security log after you set the Security
registry value to 1, the computer still stops responding when an audit
Description of the AutoBackupLogFiles registry entry
Using this entry causes the Event Log service to automatically
clear a full event log and to back up the log file. On computers with the
"CrashOnAuditFail" policy turned on, the computer continues to log events
(instead of hanging because of an audit failure) if the current log file can be
backed up automatically. By default, event logs are stored in the
%SystemRoot%\System32\Config folder. If you turn on this registry value, a full
log file is automatically backed up in the %SystemRoot%\System32\Config folder,
the log file is cleared, and event logging resumes.
If you turn on
this registry value, you must make sure to move or delete the backup log files
from the System volume. If you do not, the volume may become full. Microsoft
recommends that you implement a manual or automated procedure to move or delete
the backup log files to prevent the backup log files from consuming all of the
space on the System volume. If you turn on this registry value, take immediate
action if you receive a "Disk full" message.
When a log file is
successfully backed up, event 524 is logged with a source of "eventlog" in the
Security event log file. The event is similar to:
The Security log file was saved as Security-2002-02-05-22-48-40-042.evt because the current log file is full.
The name of the backup file is a concatenation of the log file
name and the date and time (in coordinated universal time, or UTC). The name
has this format:
The backup log file name will look similar to this:
Turning this registry value on or off affects all of the log
files. The change takes effect after you restart the computer, or clear any
For more information about how to obtain a hotfix for Windows 2000
Datacenter Server, click the following article number to view the article in the Microsoft Knowledge Base:
The Datacenter Program and Windows
2000 Datacenter Server product
For more information about how to install multiple hotfixes with
only one reboot, click the following article number to view the article in the Microsoft Knowledge Base:
How to install multiple Windows
updates or hotfixes with only one reboot