How to Delete the Proxy Cache on IE
The cache stores temporary files and data that are collected from the various websites you visit while browsing the Internet, including any proxy servers you visit. Delete the cache to clear out old files stored on your browser and to get rid of any records of your Internet habits. Internet Explorer includes all the necessary utilities to manage the Internet files and folders on your computer.
Open an Internet Explorer window.
Click the "Tools" button and click "Safety.
Click "Delete Browsing History" in the sub-menu. Click the "Temporary Internet Files" and "Cookies" check box. Click "Delete" to clear the proxy cache files from your web browser.