true if the user was deleted; otherwise, false.
Users deleted from the database are only deleted from the configured applicationName.
If deleteAllRelatedData is true, user data stored in the database for the System.Web.Security.Roles, System.Web.HttpContext.Profile, or System.Web.UI.WebControls.WebParts.WebPart personalization is also deleted when you are using the System.Web.Security.SqlRoleProvider, System.Web.Profile.SqlProfileProvider, and System.Web.UI.WebControls.WebParts.SqlPersonalizationProvider objects for data storage.