Isolated storage is the final aspect of .NET runtime security we discuss. Isolated storage is a data storage mechanism that allows managed code to store user and application-specific data to disk. The use of isolated storage simplifies programming and minimizes the security risks associated with allowing code to store data to a computer's hard drive. In this chapter, we describe what isolated storage is and explain where it provides benefits over existing data storage options. We demonstrate how to use isolated storage in your own programs, as well as how to administer and control access to it.