Stop Internet Explorer 8 and later from remembering your passwords
Internet Explorer 8 and later (verified to version 11)
To remove a stored password or other stored information in Internet Explorer:
From the Tools menu, select Internet Options.
On the General tab, under “Browsing history”, click Delete… .
Check the item(s) you want to delete:
Temporary Internet files: Copies of web pages, images, and media that are saved for faster viewing
History: A list of visited sites
Download history (Internet Explorer 9 only): A list of downloaded files
Form data: Saved information you entered in forms
ActiveX Filtering and Tracking Protection data (Internet Explorer 9) or InPrivate Filtering data(Internet Explorer 8): Saved data to detect where web sites may be automatically sharing details about your visit
To delete everything, uncheck Preserve Favorites website data and check all the other options.