. Nothing is installed, and the system returns to its previous OS once you pop the LiveCD out.
Some LiveCDs come with an installation utility launchable from a desktop icon that can optionally install the system on a hard drive or USB keydrive. Most LiveCDs can access too the information on internal and/or external harddrives, diskettes and USB Flash memories (i.e. to store data -home directory- or to be used like rescue systems).
For example, in Dynebolic the nest file is called dynebol.nst and it keeps all your home and settings inside (/home, /etc, /var, /tmp). The available space for your nest is found by dyne:bolic thru your partitions on harddisk or usb storage devices (like usb pens, smartcards or even photo cameras). This approach doesn't requires any change in the data structure of the partitions: just one file is created (dynebol.nst).
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