This article explains how to manage AutoComplete in Internet Explorer 11. It also contains information on how to disable AutoComplete completely.
How to Clear AutoComplete History in Internet Explorer® 11 on a Windows® 8.1 PC
The AutoComplete feature in Internet Explorer 11 saves the text you type into the browser's address bar and web forms for later use. This way, text fields are filled in automatically when you type something familiar. Change the AutoComplete settings for IE 11 to specify which data components are used. Here's how:
Select the gear in the top right corner of the browser window and choose Internet Options.
In the Internet Options dialog box, go to the Content tab.