Date: April 30, 2005
Subject: Maintaining a Hard Drive

Although most computers today are evaluated on the basis of their speed or their graphics capability once they have been set up and used for a period of time the hard drive will become the single most important component of the computer. The hard drive holds the operating system, applications and the data that will eventually have a greater value than the computer itself.

From a performance standpoint as well the hard drive is a critical component, it is frequently the hard drive that is responsible for the general decrease in performance of the computer over time. When a computer is first set up the hard drive is at its performance peak. As the computer is used its performance begins to degrade, not significantly but noticeably. The system may take longer to power up, applications may take longer to load and documents may require more time to be opened or to move from page to page.

Microsoft Windows includes three utilities that can help you to keep your hard disk operating at peak performance:

1/ Disk Cleanup - removes unnecessary temporary files

2/ Disk Defragmenter - optimizes file storage on the hard disk

3/ Error Checker - checks the hard disk for errors

Although each of these utilities is available in all current version of Microsoft Windows I will be discussing them from the point of view of Windows XP Pro.

1/ Disk Cleanup - As you use your computer many applications will save temporary files on your hard disk. Internet browsers (such as Internet Explorer, Opera and Firefox) will store copies of all the web pages you visit in a special cache that is generally many mega-bytes in size. Deleted files and documents will gradually fill the Recycle Bin. Windows itself will store an ever growing list of files in its own temporary folders. Not only do these files occupy disk space but quite often Windows and other applications will require more time to manage these resources, reducing the overall performance of the system. The Disk Cleanup utility analyzes the hard disk and locates temporary files that can be deleted in order to free up disk space and reduce system overhead.

To access Disk Cleanup follow the menus:

START => ALL PROGRAMS => ACCESSORIES => SYSTEM TOOLS

and click on "DISK CLEANUP." After a few moments of analysis the utility will report the size of the files stored in the various temporary locations and give you the option to choose which you would like to delete. Place a check mark next to each location you wish to empty and then click "OK" to begin the process of deleting the associated files. Please note that this process is not reversible, once the files have been deleted they cannot be recovered.

2/ Disk Defragmenter - The hard disk of a computer serves much the same purpose and function as the bookshelves at a library; both store data in an organized fashion so that it can be easily found, retrieved and used. Additionally, both the library and your hard disk will experience an ever increasing level of disorganization as they are used. Initially all data on the hard disk will occupy the first storage areas (sectors) of the hard disk and can therefore be quickly retrieved with a minimum of searching. As time goes by and applications and documents are added, modified or deleted this will no longer be the case. Data will begin to be scattered on the hard disk where ever it will fit. This is called fragmentation and simply means that a file will be scattered over many areas of the hard disk rather than in a single location. This causes the hard disk to spend more time looking for the various parts of a file and can therefore reduce system performance. The Disk Defragmenter simply ensures that all the files on the hard disk are stored in one location and that no file is scattered all over the hard disk.

To access the Disk Defragmenter follow the menus:

START => ALL PROGRAMS => ACCESSORIES => SYSTEM TOOLS

and click on "DISK DEFRAGMENTER." On the lower left of the Disk Defragmenter screen are two buttons:

1/ Analyze - Analyzes the level of fragmentation on the hard disk

2/ Defragment - Performs an analysis and begins the defragmentation process

Select the second option to start defragmenting the hard disk. Depending on the amount of data on your hard disk and the speed of your computer this process could take several hours so it would be best to start it when will be away from your computer for some time.

3/ Error Checker - Although hard disks are more reliable today than at any point in the past they are a mechanical component and so are subject to wear and tear. Due to the speed at which they rotate (typically 7,200 rotations per minute) any sudden movement or shock while the hard disk is in operation can cause serious damage. The Error Checker included with Windows XP can examine a hard disk for errors and in many cases repair them. There are two principle types of errors that can occur on a hard disk:

1/ File errors - These errors are generally repairable, though occasionally with some data loss, and occur when the hard disk's index contains invalid information about the location and/or size of various files

2/ Physical errors - These errors can often not be repaired and occur when a defect exists in the structure of the hard disk

To access the Error Checker click on the My Computer icon either on your desktop or in the Start Menu and right click on the hard disk you wish to check for errors. Click on the Properties sub-menu, then on the Tools tab and select "Error-Checking." A new window with two check box options will appear.

1/ Automatically fix file system errors - will automatically repair file errors without user intervention and is the recommended setting

2/ Scan for and attempt recovery of bad sectors - will cause the Error Checker to examine the hard disk for physical errors and attempt to repair them, a process which could take in excess of an hour on larger hard disks or slower systems.

Once the Error Checker is complete it will display a simple analysis of the errors it found and whether it was able to repair them or not. If the Error Checker finds physical errors you should consider replacing the hard disk before data is lost (or at the very least ensure that you regularly backup the data on the hard disk).

Note - Both the Disk Defragmenter and the Error Checker must have exclusive use of the hard disk to operate successfully. If you find that they continually restart please contact us and we can help you.

As always, please do not hesitate to contact me if you have any questions about this or any other issue.

If you have an associate who you think would also appreciate receiving these bulletins please let me know (with their approval) and I will add them to the bulletin mailing list. Please feel free to forward these bulletins to anyone you wish. If you no longer wish to receive these bulletins, or if you received this bulletin by mistake please send me an email with "Please remove me" in the subject line and I will take your name off of the bulletin mailing list.