Event Viewer, a component of
MicrosoftMicrosoft Corporation is a multinational computer technology corporation that develops, manufactures, licenses, and supports a wide range of software products for computing devices...
's
Windows NTWindows NT is a family of operating systems produced by Microsoft, the first version of which was released in July 1993. It was originally designed to be a powerful high-level-language-based, processor-independent, multiprocessing, multiuser operating system with features comparable to Unix. It was...
line of
operating systemAn operating system is an interface between hardware and user which is responsible for the management and coordination of activities and the sharing of the resources of the computer that acts as a host for computing applications run on the machine. As a host, one of the purposes of an operating...
s, lets administrators and users view the
event logsComputerized data logging is the process of recording events, with an automated computer program, in a certain scope in order to provide an audit trail that can be used to understand the activity of the system and to diagnose problems....
on a local or remote machine. In
Windows VistaWindows Vista is a line of operating systems developed by Microsoft for use on personal computers, including home and business desktops, laptops, tablet PCs, and media center PCs...
, Microsoft overhauled the event system and renamed it to
Windows Event Log.
Windows NT has featured event logs since its original release in 1993. Applications and operating system components can make use of this centralized log service to report events that have taken place, such as a failure to start a component or complete an action.
Event Viewer, a component of
MicrosoftMicrosoft Corporation is a multinational computer technology corporation that develops, manufactures, licenses, and supports a wide range of software products for computing devices...
's
Windows NTWindows NT is a family of operating systems produced by Microsoft, the first version of which was released in July 1993. It was originally designed to be a powerful high-level-language-based, processor-independent, multiprocessing, multiuser operating system with features comparable to Unix. It was...
line of
operating systemAn operating system is an interface between hardware and user which is responsible for the management and coordination of activities and the sharing of the resources of the computer that acts as a host for computing applications run on the machine. As a host, one of the purposes of an operating...
s, lets administrators and users view the
event logsComputerized data logging is the process of recording events, with an automated computer program, in a certain scope in order to provide an audit trail that can be used to understand the activity of the system and to diagnose problems....
on a local or remote machine. In
Windows VistaWindows Vista is a line of operating systems developed by Microsoft for use on personal computers, including home and business desktops, laptops, tablet PCs, and media center PCs...
, Microsoft overhauled the event system and renamed it to
Windows Event Log.
Overview
Windows NT has featured event logs since its original release in 1993. Applications and operating system components can make use of this centralized log service to report events that have taken place, such as a failure to start a component or complete an action. The system defines three log sources:
- "System"
- "Application"
- "Security
The Security Log, in Microsoft Windows, is a log that contains records of login/logout activity and/or other security-related events specified by the system's audit policy. Auditing allows administrators to configure Windows to record operating system activity in the Security Log. The Security Log...
"
Microsoft intends the System and Application log sources for use by the Windows operating system and Windows applications respectively. Only the
Local Security Authority Subsystem ServiceLocal Security Authority Subsystem Service , is a process in Microsoft Windows operating systems that is responsible for enforcing the security policy on the system. It verifies users logging on to a Windows computer or server, handles password changes, and creates access tokens...
(lsass.exe) can directly write to the
Security logThe Security Log, in Microsoft Windows, is a log that contains records of login/logout activity and/or other security-related events specified by the system's audit policy. Auditing allows administrators to configure Windows to record operating system activity in the Security Log. The Security Log...
.
The Event Viewer uses event IDs to define the uniquely identifiable events that a Windows computer can encounter. For example, when a user's
authenticationAuthentication is the act of establishing or confirming something as authentic, that is, that claims made by or about the subject are true...
fails, the system may generate Event ID 672.
Windows NT 4.0Windows NT 4.0 is a preemptive, graphical and business-oriented operating system designed to work with either uniprocessor or symmetric multi-processor computers. It was the next release of Microsoft's Windows NT line of operating systems and was released to manufacturing on 31 July 1996...
added support for defining "event sources" (i.e. the application which created the event) and performing backups of logs.
Windows 2000Windows 2000 is a line of operating systems produced by Microsoft for use on business desktops, notebook computers, and servers. Released on February 17, 2000, it was the successor to Windows NT 4.0, and is the final release of Microsoft Windows to display the "Windows NT" designation...
added the capability for applications to create their own log sources in addition to the three system-defined "System", "Application", and "Security" log files. Windows 2000 also replaced NT4's Event Viewer with a
Microsoft Management ConsoleThe Microsoft Management Console is a component of Windows 2000 and later Windows NT-based operating systems that provides system administrators and advanced users with a flexible interface through which they may configure and monitor the system....
(MMC) snap-in.
Windows Server 2003Windows Server 2003 is a server operating system produced by Microsoft. Introduced on 24 April 2003 as the successor to Windows 2000 Server, it is considered by Microsoft to be the cornerstone of its Windows Server System line of business server products. An updated version, Windows Server 2003...
added the
AuthzInstallSecurityEventSource API calls so that applications could register with the security event logs, and write security audit entries.
Versions of Windows based on the Windows NT 6.0 kernel (
Windows VistaWindows Vista is a line of operating systems developed by Microsoft for use on personal computers, including home and business desktops, laptops, tablet PCs, and media center PCs...
and Windows Server 2008) no longer have a 300-megabyte limit to their total size. Prior to NT 6.0, the on-disk files were opened as
memory-mapped fileA memory-mapped file is a segment of virtual memory which has been assigned a direct byte-for-byte correlation with some portion of a file or file-like resource. This resource is typically a file that is physically present on-disk, but can also be a device, shared memory object, or other resource...
s in kernel memory space, which used the same memory pools as other kernel components.
Windows Event Log
Windows Event Log is the rewritten event tracing and logging architecture introduced with Windows Vista. Windows Event Log has been rewritten around a well-defined structured
XMLXML is a set of rules for encoding documents electronically. It is defined in the produced by the W3C and several other related specifications; all are fee-free open standards....
log-format and a designated log type to allow applications to more precisely log events and make it easier for support technicians and developers to interpret the events. The XML representation of the event can be viewed on the
Details tab in an event's properties. It is also possible to view all potential events, their structures, registered
event publishers and their configuration using the
wevtutil utility, even before the events are fired. There are a large number of different types of event logs including Administrative, Operational, Analytic, and Debug log types. Selecting the
Application Logs node in the
Scope pane reveals numerous new subcategorized event logs, including many labeled as diagnostic logs. Analytic and Debug events which are high frequency are directly saved into a trace file while Admin and Operational events are infrequent enough to allow additional processing without affecting system performance, so they are delivered to the Event Log service. Events are published asynchronously to reduce the performance impact on the
event publishing application. Event attributes are also much more detailed and show EventID, Level, Task, Opcode, and Keywords properties.
Users can filter event logs by one or more criteria or by a standard XPath 1.0 expression, and custom views can be created for one or more events. Using XPath as the query language allows viewing logs related only to a certain subsystem or an issue with only a certain component, archiving select events and sending traces on the fly to support technicians.
Filtering Using XPath 1.0
- Open Windows Event Log
- Expand out Windows Logs
- Select the log file that is of interest to you (In the example below, we use the Security event log)
- Right-click on the Event Log and select Filter Current Log...
- Change the selected tab from Filter to XML
- Check the box to Edit query manually'
- Paste your query into the text box. You will find sample queries below.
Here are examples of simple custom filters for the new Window Event Log:
-
- Select all events in the Security Event Log where the account name involved (TargetUserName) is "JUser"
-
- Select all events in the Security Event Log where the string "JUser" is present as data anywhere in the EventData section
-
- Select all events in the Security Event Log where the strings "JUser" or "JDoe" are present as data anywhere in the EventData section
-
- Select all events in the Security Event Log where the string "JUser" is present as data anywhere in the EventData section and the Event ID is "4471"
-
Event Subscribers
Major event subscribers include the Event Collector service and
Task SchedulerTask Scheduler is a component of Microsoft Windows that provides the ability to schedule the launch of programs or scripts at pre-defined times or after specified time intervals. It was first introduced in the Windows 95 Plus! pack as System Agent but was renamed to Task Scheduler in Windows 98...
2.0. The Event Collector service can automatically forward event logs to other remote systems, running
Windows VistaWindows Vista is a line of operating systems developed by Microsoft for use on personal computers, including home and business desktops, laptops, tablet PCs, and media center PCs...
, Windows Server 2008 or Windows Server 2003 R2 on a configurable schedule. Event logs can also be remotely viewed from other computers or multiple event logs can be centrally logged and monitored agentlessly and managed from a single computer. Events can also be directly associated with tasks, which run in the redesigned
Task SchedulerTask Scheduler is a component of Microsoft Windows that provides the ability to schedule the launch of programs or scripts at pre-defined times or after specified time intervals. It was first introduced in the Windows 95 Plus! pack as System Agent but was renamed to Task Scheduler in Windows 98...
and trigger automated actions when particular events take place.
External links