There’s a special storage location for a .NET application on Windows that is allocated to that application. It’s called isolated storage and it’s an optimal place to store files by an application that doesn’t have full access to the file system. Writing to and reading from isolated storage doesn’t require any extra security check. An application without full access to the file system will be able to use its allocated slot in isolated storage and nothing else. It’s an ideal mechanism for storing e.g. application state.
However, don’t confuse isolated storage with file security. It is still a “normal” location on disk with a file path. A typical location is under users/[username]/appdata/local. Therefore you or full-trust applications can still find and modify the files saved in isolated storage. However, limited-trust applications won’t be able to access any other part of the file system.
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