Backups And Images: What Are They?

Dennis Faas's picture

I have been getting many questions lately about imaging and backup software. Since so many users have had questions about it, I decided there might be other folks that had similar questions, but were too shy to ask.

OK -- so what is Imaging and what is Backup Software?

Imaging and backup software fulfils very important roles in computer maintenance. However, the need and use for each is very different and that difference will determine which software you will need to support your system.

The Backup

Typically, a backup creates a 'copy' of any file that is NOT in use. If the file is 'open' and being used by the system, such as the registry in Windows, it will not be 'copied'. To create a backup, the only consideration is what to back up and where to back it up to. A backup can be easily used to restore one or more individual data files, such as in My Documents.

Restoring installed programs can be a bit problematic, however, since the registry file that contains critical information will not be available. The fix, in that situation, would be to reinstall the program, which limits the advantages of a backup.


An Image, on the other hand, is simply a 'snapshot' (a bit-by-bit copy) of the drive being 'imaged'. That means that the condition of any file is literally frozen in time in the image created, including any 'open' files, such as the registry.

An Image can restore the entire drive in situations where things get so bad it means rebuilding the system from scratch. Restoring a single or group of files from an image can be done but, because data file location information included in the image could damage a file or two that occupy the same location on your drive, you run the risk of causing more damage than you had before the attempt.

In an image creation process, you will want to clean the system of everything you do not want to restore before the process is started (virus, Spyware, adware, unwanted data files, etc.) That's why it's always good to make an image of a fresh install of Windows so you can always go back to it if needed.

Backup and Image Frequency

The professional System Administrator will run a nightly backup, keeping it on media that is removed from the system immediately after creating it. Of course, I am speaking about a system that has several users creating and updating all sorts of things on the system. For the home user, taking a backup may turn out to be once a week or even monthly.

A disk image is done on far less frequently. Perhaps once a year would be reasonable for the home user.

Both processes have good solid reasons for being used, but they answer entirely different needs, so consider carefully what you want to do and why, before buying anything. Then go for the best 'bang' for the dollar! ;-)

I hope I managed to blow some of the smoke away for you. Have Fun!

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