What does it mean for a program to run in a Virtual Sandbox?
Running in a sandbox means that a program is isolated in a secure environment with a synthetic view of a user configurable subset of files and the registry, the operations upon which will all be discarded when the sandbox is closed. By default, programs running in a sandbox are not allowed to make any actual modifications to real files or registry keys on a system, but can only make changes visible inside of the sandbox.
Programs running in a sandbox appear on the Windows desktop alongside other applications. By default, programs running in a sandbox have a view of files and the registry similar to a freshly installed Windows base system with a single user account called SyntheticUser.FGVS.x, no personal files, and no local network.