Access General preferences by going to OpenOffice.org Writer's EndNote menu and selecting Cite While You Write Preferences or by clicking the Cite While You Write Preferences icon on the EndNote toolbar.
Open EndNote When Starting OpenOffice.org Writer: Select this item to always open EndNote when you start OpenOffice.org Writer.
Close EndNote When Leaving OpenOffice.org Writer: Select this item to always close EndNote when you leave OpenOffice.org Writer. (It does not work if EndNote was already open before you started Writer.)