Troubles with plugins

I just installed WP and it was fine, until I added some plugins, and now all I get is

“object(Auto_Plugin_Upgrader)#226 (5) { [“result”]=> NULL [“bulk”]=> bool(false) [“show_before”]=> string(0) “” [“strings”]=> array(0) { } [“skin”]=> object(Headless_Skin)#227 (8) { [“text”]=> NULL [“plugin”]=> string(0) “” [“plugin_active”]=> bool(false) [“plugin_network_active”]=> bool(false) [“upgrader”]=> NULL [“done_header”]=> bool(false) [“result”]=> bool(false) [“options”]=> array(5) { [“url”]=> bool(false) [“nonce”]=> string(0) “” [“title”]=> string(0) “” [“context”]=> bool(false) [“plugin”]=> string(0) “” } } }
Fatal error: Class ‘ZipArchive’ not found in /home/acnecare/public_html/wp-content/plugins/wordpress-background-update/wordpress-background-update.php on line 140″

What can I do to fix this?

Thanks