An Image System also called "Ghost Image" or "Ghost" because of a software solution strong-known is a backup of the entire contents of a partition (or even the entire multiple partitions). No distinction is made in this content. We can say that an image system is the "photocopy" of the partition at the moment T (T is the time of backup).
It must distinguish between the image system data backup. Typically, the data are stored continuously or regularly, selecting the directories to take into account and often incremental manner.
The system change infrequently and there is no interest in an image frequently. To create an image, we must choose the partition and not directories. The backup is to preserve everything that is specified first, and then only files modified in the future by keeping separate copies of the original file. Backing up data and image system are far removed from their purpose and their method.
1 - Why Do you Need It?
Anything can happen! A virus or trojan or a spyware, put panic into the system. The installation or upgrade software or a driver has made the system unstable, or worse, out of service. Electric shock destroyed components (motherboard ).
However, Windows XP requires reinstall if there is a change of motherboard (unless it is replaced by another identical characteristics).
How long will you lose? Reinstall Windows, and it just will last at least 1 hour! To this, add installation time peripherals and software! I do not know about you but in my case, reinstall Windows from the start cost me at least 1 week! Many software, all settings of custom applications and system security and patch ... All this by step to validate the stability and while I have other emergencies!
Hence the need to create a system image. The creation takes me 3 minutes of preparation and lasts 30 minutes while restoring the image is completed in 15 minutes (Athlon 2400xp +, 1GB of RAM, Windows disk and an 12 GB is filled to 10 GB).