This property controls how Studio interacts with the Internet Explorer Browser target. If you set this property to True, Studio ignores the Browser control while the project is running. The Browser events or methods are not applicable for use in automations in this case (with the exception of the base events such as Created and Destroyed).
Keep in mind...
Property Use - Only set the property to True if the web application freezes while running your project when additional web application windows open, such as Alert Panels.
Exceptions - This property only applies to the main (top-level) browser control. If the application contains browser controls within frames, all events and methods for these browsers are hooked by Studio and the browser events/methods are applicable.
You might uncheck it if you wanted to interrogate the WebBrowser control. This is useful as it has a Navigate method you can call to pass a new URL to your adapter (i.e. if you wanted to navigate somewhere you couldn't click a link or something to get to).