How to Use a Multiple Proxy
- 1). Click the Start menu and select "Control Panel." Switch to "Classic View" located on your left pane.
- 2). Double-click "Internet Options."
- 3). Click the "Connections" tab. Click the button labeled "LAN Settings."
- 4). Locate and click the "Advanced" button under the sub-heading "Proxy server."
- 5). Type the proxy server addresses you wish to use under the respective fields: "HTTP," "Secure," "FTP" and Socks."
- 6). Click "OK" and then "Apply" to end task.
Source...