winforms - C# Database not saving -

i've linked microsoft access database visual studio project , using data sources have included data grid view modify data. when dragged , dropped data grid view onto project automatically added tool strip when try save modified data pressing save icon won't save permanently, meaning can't close program , re-open same changes.

i looked @ code save button , changed official microsoft support page code displays message if saves , if not, though it's telling me it's saved correctly when re-open project no changes has been saved?

here's code save button have far:

private void modulesbindingnavigatorsaveitem_click(object sender, eventargs e)     {         try         {             this.validate();             this.modulesbindingsource.endedit();             this.modulestableadapter.update(this.modulesdatabasedataset.modules);             messagebox.show("saved succesfully","save success",messageboxbuttons.ok,messageboxicon.information);         }         catch (system.exception ex)         {             messagebox.show("unable save. make sure modified data correct data type.","save failed",messageboxbuttons.ok,messageboxicon.error);         }     }