Event Viewer

The Event Viewer window can be accessed through Start, Programs, Administrative Tools, Event Viewer. There are three categories of logs that you can view. The first is Application, which shows all the events for the Windows applications. These log entries will indicate errors if an application did not start correctly or if it ended abruptly.
The second log is the Security events. This log is useful for log in errors if you're a network administrator. it can show failed attempts to log on and how many times they happened. This could indicate someone is attempting to discover passwords or you may just need to re-train an employee in the use of log in names and password security. The only program that has access to write to this file is the lsass.exe also known as the Local Security Authority Subsystem Service.
The last log is the System events. This file is an event list the operating system uses. Some of the information written to this file references operating system information and errors that may have occurred. It also displays general information on programs as they enter running states such as Windows Firewall.
Occasionally you will want to view these events to verify your system is running correctly without errors. If you do see an error, you can highlight the error and right click the mouse button. When the menu appears, click on Properties and it will give you a description of the error. This will show information on the file or device that generated the event. You can also select the "more information" web link to Microsoft and it can give you a more detailed description and possible actions to take to correct the error.