Have you ever wanted to reset your computer completely to the way it was when you first bought it? Or maybe you have installed or deleted something you really wish you hadn't? In that case what you really needed was a disk image. ODIN, or "Open Disk Imager in a Nutshell" is a program that saves or restores disk-images. A disk image is a snapshot of your harddrive at a given time, almost like taking a picture of it so that you can restore it exactly as it was at a later time. So if you buy a new computer, you could take a snapshot of the harddrive as it was when you first got the computer, and if you get into trouble later, or perhaps need to replace the harddrive, all you have to do is restore the image again.
With ODIN you can copy the entire harddrive, or just the parts of it that has been used if you want to make the image-file smaller. The program is small, and can be run from a external media like a memory stick
To use ODIN, download the zip-file and unzip it to your harddrive or memory stick, and then start ODIN.exe. In the program you first select if you want to restore an old image, or save a new one. Then select the partision to save image from, and choose start. You can also make ODIN compress the data for you, to make the file smaller, or divide it up into smaller parts so that you are able to save the image to CD's or DVD's.