1. In IE click on Tools and Internet Options (you can also get to this through the windows control panel)

2. Click on the tab labeled Content then click on the Auto Complete button.
3. To reset the usernames and passwords in IE, click on the Clear Passwords button.
4. If you would like to turn off the Auto Complete feature for username and passwords, remove the check from the "Use AutoComplete for User names and passwords on forms" box.