The Yahoo toolbar, if you care, is a handy toolbar that gives you many Yahoo services right from your browser’s toolbar. It started as a bookmark and a pop up blocker but it has since evolved to a very useful application sitting in your browsers toolbar.
To Install Yahoo toolbar in Internet explorer, simply launch Internet Explorer and go to the Yahoo Toolbar page. https://toolbar.yahoo.com
The Yahoo Toolbar page will detect the browser you are using and prepare the appropriate download for you. Simply click on the green Download button on the right side of the page.
The application will be downloaded to your computer. Find it and double click on it to install. You will need to restart your browser.
You can read more about the Yahoo Toolbar here.