Some preventive maintenance consists of cleaning, inspecting, and doing minor repairs. Some preventive maintenance uses application tools that are either already in the operating system or can be loaded onto the user's hard drive. Most preventive maintenance applications can be set to run automatically according to a schedule.

Windows has the following utilities that launch tasks when you schedule them:

• The DOS AT command launches tasks at a specified time using the CLI.
• The Windows Task Scheduler launches tasks at a specified time using a GUI.

Information about the AT command is available at this path in Windows XP:

Start > Run > Type cmd and press Enter

Then type AT /? at the command line.

In Windows Vista, access the command line using the following path:

Start > Start Search > Type cmd and press Enter

Access the Windows Task Scheduler by following this path in Windows XP:

Start > All Programs > Accessories > System Tools > Scheduled Tasks

In Windows Vista, follow this path:

Start > All Programs > Accessories > System Tools > Task Scheduler

Both of these tools allow you to run a command once at a specific time or schedule a command to run on selected days or times. The Windows Task Scheduler, shown in Figure 1, is easier to learn and use than the AT command, especially when it comes to recurring tasks and deleting tasks already scheduled.

System Utilities
Several utilities included with DOS and Windows help maintain system integrity. Two utilities that are useful tools for preventive maintenance are:

• ScanDisk or CHKDSK – ScanDisk (Windows 2000) and CHKDSK (Windows XP and Vista) check the integrity of files and folders and scan the hard disk surface for physical errors. Consider using ScanDisk or CHKDSK at least once a month and also whenever a sudden loss of power causes the system to shut down.
• Defrag – As files increase in size, some data is written to the next available space on the disk. In time, data becomes fragmented, or spread all over the hard drive. It takes time to seek each section of the data. Defrag gathers the noncontiguous data into one place, making files run faster.

You can access both of these utilities by using this path in Windows XP:

Start > All Programs > Accessories > System Tools > Disk Defragmenter

In Windows Vista, use this path:

Start > Computer > right-click Drive x > Properties > Tools

Automatic Updates
If every maintenance task had to be scheduled every time it was run, repairing computers would be much harder than it is today. Fortunately, tools such as the Scheduled Task Wizard allow many functions to be automated. But how can you automate the update of software that has not been written?

Operating systems and applications are constantly being updated for security purposes and for added functionality. It is important that Microsoft and others provide an update service, as shown in Figure 2. The update service can scan the system for needed updates and then recommend what should be downloaded and installed. The update service can download and install updates as soon as they are available, or it can download updates as required, and install them when the computer is next rebooted. The Microsoft Update Wizard is available at this path in Windows XP:

Start > Control Panel > System > Automatic Updates

In Windows Vista, it is available at this path:

Start > Control Panel > Windows Update

Most antivirus software contains its own update facility. It can update both its application software and its database files automatically. This feature allows it to provide immediate protection as new threats develop.

Restore Point
An update can sometimes cause serious problems. Perhaps an older program is in the system that is not compatible with the current operating system. An automatic update might install code that works for most users but does not work with your system.

You can solve this problem by creating a restore point, which is an image of the computer settings. If the computer crashes or an update causes system problems, the computer can roll back to a previous configuration. You can use the Windows Restore Point utility, as shown in Figure 3, to create and revert to a restore point.

A technician should always create a restore point before updating or replacing the operating system. Restore points should also be created at the following times:

• When an application is installed
• When a driver is installed

NOTE: A restore point backs up drivers, system files, and registry settings but not application data.

To restore or create a restore point, use the following path:

Start > All Programs > Accessories > System Tools > System Restore

Backup Status and Configuration
Windows Vista has the Backup Status and Configuration tool for backing up photos, music, email, and other types of user data. Backups can be set to run automatically at regular intervals. Back up your data to a drive other than the drive that contains the operating system. The Backup Status and Configuration tool is not used to back up system settings. Windows Vista Home Basic does not include the option to set automatic backups. To access the Backup Status and Configuration tool, use the following path:

Start > All Programs > Accessories > System Tools > Backup Status and Configuration

ERD and ASR
Windows 2000 offers the ability to create an emergency repair disk (ERD) that saves critical boot files and configuration information necessary to troubleshoot problems in Windows. Windows XP offers the same features with the Automated System Recovery (ASR) wizard. Although both ERD and ASR are powerful troubleshooting tools, they should never replace a good backup.

A recovery disc contains the essential files used to repair the system after a serious issue, such as a hard drive crash. The recovery disc can contain the original version of Windows, hardware drivers, and application software. When the recovery disc is used, the computer is restored to the original default configuration.

Lab Restore Points in Windows XP Create a restore point and return your computer back to that point in time. Optional Lab Restore Points in Windows Vista Create a restore point and return your computer back to that point in time.