Removing these drop down menus items consists of clearing your browsing history, web cookies and cache. Once you do that, the only drop-down menu items that might display in the address bar will be those that correspond to your Bookmark or Favorite links. The specific steps to perform these adjustments will vary depending on your browser, but the general process is the same.
To clean Internet Explorer 8 and above cache, History, Cookies:
1> From the safety menu in the upper right, click Delete Browsing History
2> Deselect Preserve Favorites websites data, and select Temporary Internet files, cookies and history
3> Click Delete
You can also take tool to clean the cache, history, cookies with an easy manner. I high recommend you take C cleaner or Cloud System Booster.
Here you can have a detail view
Hope this can help you. Good luck.