This policy setting prevents users from deleting the history of Web sites the user has visited. This feature is available ...

This policy setting prevents users from deleting the history of Web sites the user has visited. This feature is available in the Delete Browsing History dialog box. 

If you enable this policy setting, Web sites that the user has visited will be preserved when the user clicks Delete.

If you disable this policy setting, Web sites that the user has visited will be deleted when user clicks Delete. 

If you do not configure this policy setting, the user will be able to select whether to delete or preserve Web sites the user has visited when the user clicks Delete.

If the "Turn off Delete Browsing History functionality" policy is enabled, this policy is enabled by default.