Both Windows 9x and 2000 have many system
tools that are helpful when troubleshooting. They can provide a number
of administrative and diagnostic tools to help fix problems with the
computer system.
Event Viewer

The Event Viewer in Windows 2000 is used to monitor system events,
application events, and security events. System events include things
like successful and failed Windows component startups. Application
events store information about the system applications and their
performance. Security events store events related to system security
like logons and logoffs, file and folder access, and the creation of a
new Active Directory. The Event Viewer also creates categories of
system and application events. Information Events indicate that an
application, service, or driver has loaded successfully. Warning
Events warn about things that might be harmful in the future. Error
Events indicate that an application, service, or driver has failed to
load. Because the security log is limited in size, and because a large
number of routine audit records can make it difficult to find records
that suggest a security problem, carefully consider how to audit
object access. Generating too many audit records will require that the
security log be reviewed and cleared more often than is practical.
This will generate a message stating, "Event Log is Full".
When this happens, open the event log and delete some of the entries.
Dr. Watson TSR Utility
The Dr. Watson utility is used to isolate and correct General
Protection Faults (GPF). When the cause of the GPF cannot be traced to
the operating system, it is almost certainly caused by an application.
The Dr. Watson utility can be started to run in the background as an
application runs. The utility monitors application operations and logs
the key events in the DRWATSON.LOG file. This log provides details
about the events that caused the GPF. If the error repeats in the same
application, the software may need to be updated with a patch.
SCANREG.EXE

The SCANREG.EXE file is used to scan the registry for corruption. If
system troubleshooting seems to indicate that an error is caused by a
corrupted registry entry then run this executable. If the scan does
produce any corrupted files, try to repair them by inserting the
installation CD and choosing the repair installation option.
DEFRAG.EXE
System performance can be degraded when the files are fragmented on
the hard drive. Over time, files get added and erased from the hard
drive and pieces of files get scattered through the hard drive. This
will degrade performance and can also cause the system or applications
to lock up. Run the DEFRAG.EXE file to start the Defrag utility. This
will rewrite all the files on the hard drive back to the beginning of
the drive, making it easier and faster for the hard drive to retrieve
the information.
CHKDSK.EXE
The CHKDSK utility is a command-line tool that is used to recover lost
allocation units from the hard drive. The lost allocation units occur
when an application terminates unexpectedly. Over time, lost
allocation units can accumulate and occupy large amounts of disk
space. By adding the /F switch to the
command, the lost
allocation units can be converted into files so they can be viewed and
deleted if necessary. This utility is used to optimize disk storage
space by locating and removing files that have been corrupted.
SCANDSKW.EXE
When using the Scandisk for Windows (SCANDSKW.EXE) disk-checking and
repair tool, check the integrity of the media (which includes hard
disks and floppy disks) to repair problems that may occur.
Windows 98, Windows 98 Second Edition, and Windows ME start Scandisk automatically when the operating system is shut down improperly or the disk contains a critical error.
MSCONFIG.EXE
Load the system tools configuration utility from the command line by
typing