Location of configuration files containing user preference settings:
%USERPROFILE%\AppData\Roaming\SQL Developer\systemx.x.xx.xx\o.ide.xx.x.x.x.xx.xx.xx\settings.xml
%USERPROFILE%\AppData\Roaming\SQL Developer\systemx.x.xx.xx\o.jdeveloper.db.connection.xx.x.x.x.xx.xx.xx\connections.xml
%USERPROFILE%\AppData\Roaming\SQL Developer\systemx.x.xx.xx\o.sqldeveloper.xx.x.x.xx.xx\product-preferences.xml