Chapter 32. System.IO.IsolatedStorage
System.IO.IsolatedStorage allows you to access an
isolated area of a filesystem for your application. This is useful
when access to the System.IO classes is not
possible. The security settings of the .NET Framework prohibit web
applications and downloaded controls from accessing the local
filesystem directly, but those settings allow them to use
System.IO.IsolatedStorage.
Applications’ storage areas are isolated from one another, so
anything in isolated storage is protected from untrusted
applications. The size of isolated storage is limited, so an
untrusted application cannot create a denial-of-service condition by
filling your hard disk with data.
When you use isolated storage, the runtime sets aside disk space
for a given level of isolation (specified using
IsolatedStorageScope).
If you use Windows 2000 or XP,
<SYSTEMDRIVE>\Documents and
Settings\<user>\Application Data contains the
isolated storage area if roaming is turned on, and
<SYSTEMDRIVE>\Documents and
Settings\<user>\Local Settings\Application Data contains the storage area if roaming is
not on. Applications can use this area as a data store for their particular
persistence needs. Figure 32-1 shows the
inheritance diagram for this namespace.
For more information, see Section 10.4 in
Chapter 10.

Figure 32-1. The System.IO.IsolatedStorage namespace