DDNS Updater is a free app that will check for any changes to the external IP address of your Windows machine. It will then update the dynamic DNS (DDNS) service if a change is detected.
You will find that DDNS Updater is fully compatible with a large number of DDNS services, thanks to its configurable HTTP API. It minimizes API calls, i.e., by persistent caching of the IP address and local IP matching. It also works with IPv4 and IPv6 (including dual-stack) and includes the ability to send an email when the detected IP address changes.
It also features configurable check and update intervals as well as running as a Windows service, so that updating occurs even when no-one is logged in.