If you no longer wish your password to be remembered, you should delete your browsing history and cookies. Cookies are the tracking devices that remember where you've been in your web browser; if you start typing www.goo
- it will auto complete and show you the full www.google.com
I'm running Internet Explorer 8 so it might vary slightly for you:
First, log out of 3FCs.
Then go to tools on your top menu
Select "Delete Browsing History"
If you want most of the history of where you've been deleted, I'd recommend making sure Temporary internet files, cookies, history and passwords are checked then press the delete button at the bottom of the window.
Depending on how many cookies you have this would take a bit. It should then be unaware that you've ever visted the site before and won't remember your username or password.
Keep in mind if you have passwords saved for other websites, it will remove those as well.