Connection Keeper is a free tool for Windows that makes sure that your Internet connection stays active, even when there has been a lengthy enough period of inactivity for the connection to shut off. This allows you to be able to instantly access the Internet whenever you need to.
It's very easy to configure, and adds a small icon to your desktop system tray. You can then program it to make the automatic disconnect become manual deactivation.
It also includes various tools like a calendar, a calculator, and supports a wide variety of skins. All of this makes Connection Keeper a comprehensive, effective tool.