Please try to do the following actions to be sure that the toolbar will display in IE9 :

1. Go to Tools -- Internet Options -- Programs -- Manage Add-ons (or directly Tools -- Manage Add-ons if such option is available). 
2. In there, you should check if all Ant.com extensions are enabled. 
3. If not, you should enable them and restart the browser. 
4. After that, you can use menu item View -- Toolbars -- Ant.com Video downloader toolbar (or Tools -- Toolbars -- Ant.com Video downloader toolbar) to enable toolbar.

For more informations about usage of Ant Toolbar under IE9, you can have a look at the following article :
http://www.ant.com/video-downloader/internet-explorer/ie9-quick