How to Disable Internet Explorer Password Caching
The dialog box that prompts you for your security credentials contains a
check box to allow you to save the password so you do not have to type the
password again when you attempt to use the same document. This is known as
"password caching." http://support.microsoft.com/?kbid=229940 (i. e. 4, 5, 6. 11/26/2003)