Item 

Description 

System variables 

Lists all environment variables and their values defined at a system level. You cannot delete an existing system variable, but you can override it.  

Add Override  

Displays the Override System Variable dialog box, allowing you to modify an existing system variable to create a new user override. This button is dimmed until you select a variable in the System variables list.  

User overrides 

Lists all defined user overrides and their values. A user override takes precedence over an existing system variable until you delete the user override.  

New 

Displays the New User Variable dialog box allowing you to create new user override to a system variable.  

Edit 

Displays the Edit User Variable dialog box allowing you to change the user override currently selected in the User overrides list.  

Delete 

Deletes the user override currently selected in the User overrides list.  

Include System Variables 

Passes the system environment variables to the application you are debugging. If unchecked, only the user overrides are passed to your application.