12.5 Using System Tools and System Editors to Troubleshoot Windows 9x/2000
12.5.1 Using system tools
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
CHKDSK.EXE 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
MSCONFIG.EXE. This is a useful troubleshooting tool that is used to interactively load device drivers and software options. With this utility, it is possible to systematically view the lines of the CONFIG.SYS and the AUTOEXEC.BAT files, and to decide whether or not to load each line. Items can be enabled or disabled until all the problems are identified.

EDIT.COM
This is a windows troubleshooting tool that can view and edit configuration (text) files such as AUTOEXEC.BAT, CONFIG.SYS, .INI files, and others.