1. A computer-implemented method for modifying a first storage medium having a plurality of files stored therein, wherein the plurality of files includes a first subset and a second subset, the method comprising: obtaining a set of metadata describing each file of the plurality of files, wherein the set of metadata includes directory information that identifies locations on the first storage medium at which the plurality of files are stored; receiving selection data that distinguish the first subset of the plurality of files that is to be unavailable for use by an end user from the second subset of the plurality of files, wherein the second subset of the plurality of files are selected files that are to be retained and available for the end user; automatically modifying a portion of the set of metadata into modified directory information metadata, wherein the modified directory information metadata corresponds to the second subset of the plurality of files to be retained; and writing the modified directory information metadata into storage locations used by an operating system for access to the retained files such that those selected files specified by the selection data are available.