As far i know giant companies like toshiba, ibm, dell, hp, etc... they all provide a recovery partition which contains the image of the OS in a state exactly when you got it first time. At the sametime they have a onetime useable backup software installed through which you can burn the image of the OS on a cd/dvd so that just in case the recovery partition is deleted you can recover the system through the cd's.
If you've used the computer for sometime and then created the restore image on a cd/dvd that will create a used image. Best practice would be to backup essential data, use the recovery partition to restore the system to original state and then use the installed software to burn an image on the cd/dvd.
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