Some packages enable you to roll up a current hard disk and then roll it out into their environment. The problem with that is they will be forced to provide the outside shell for all the true physical device drivers of that environment. If instead you install Linux from scratch, windows from scratch, whatever OS from scratch into the default instance environment you will be assured of perfect device driver activity. Also it will be much faster because they can take shortcuts and just put in stubs for stuff they know they won't need to do.