AdFender is an ad-blocking program that works independent of web browsers; it installs as a Windows program and not a browser add-on/extension and it blocks ads on all your browsers, system-wide.

There is a Firefox add-on to fix that for free. It permanently removes Yahoo mail ads and also expands your emails to always use full width of monitor screen. Just install:

'Yahoo Mail Hide Ad Panel' ( https://addons.mozilla.org/en-US/firefox... )

If you don't have Firefox browser, you can easily download and install that from here:

http://www.mozilla.org/en-US/firefox/new...

(which is the browser you should use anyway rather than IE)

While surfing on the internet if you face the advertisement problem than just add an extension or add-on in your browser i.e. ad-block which use to block all the advertisement on every website.

Google "Ad Blocker".....