Sandbox mode keeps Access from running commands that could harm your computer, such as deleting files or changing system settings.
In Access, it's possible to run dangerous VBA code in expressions — strings of instructions that Access can use to perform operations on your database. These expressions can include commands and properties that could delete files, change file attributes, start other programs, change Access settings, or change environment settings (for example, the PATH statement) on your computer. Running Access in sandbox mode helps prevent dangerous code from being run in expressions.
Important Code in a module or macro cannot be disabled by sandbox mode. To prevent macros or VBA code from being run in Access or to safely remove such code from your database altogether, you can do one or both of the following: Remove the macros or the modules that contain the code, or disconnect the modules that contain code connected to the database objects. Take care to ensure that you don't inadvertently remove functionality from your forms, reports, and other database objects.