Tested under Microsoft Windows Server 2012 R2 Foundation.

ddclient, a dynamic DNS client for Windows.

Create a SPDNS account first! You need the account information during the setup procedure of ddclient. Register a SPDNS account

Install ddclient for Windows. You can enter the configuration details during the installation or later by editing the config file in a text editor.

Here is the config file. You have to replace all <SOMETHING> fields with your SPDNS account information.

# ddclient.conf
#
daemon=5m
use=web
web=checkip.spdns.de
server=update.spdns.de
protocol=dyndns2  login=<YOUR-LOGINNAME-HERE>, password=<YOUR-PASSWORD-HERE> <YOUR-DNS-NAME-HERE>.spdns.de
ssl=no