Advanced use: reset Views module completely
WARNING: This will result in the loss of any existing views
Drops all views tables and removes the system entry so it doesn't think views was ever installed
DROP TABLE view_view;
DROP TABLE view_argument;
DROP TABLE view_filter;
DROP TABLE view_exposed_filter;
DROP TABLE view_sort;
DROP TABLE view_tablefield;
DELETE FROM system WHERE name LIKE 'views%';Then go to administer >> modules and enable views and views_ui
WARNING: This will result in the loss of any existing views