Once DynamIP has been installed as an NT Service (which is obviously only possible under Windows NT...) you can control DynamIPS (the DynamIP NT Service) like any other NT Service: from the Service Control Manager (click on the "Services" icon in your NT Control Panel to start the SCM) you can issue commands like Start, Stop, Pause, Continue, and you can set DynamIPS to Manual or Automatic start.

As long as the DynamIP NT Service is running it will ensure that DynamIP is running. Should DynamIP ever crash, DynamIPS will automatically restart DynamIP. The DynamIP settings are always read from the file DynamIPS.INI.

Detailed instructions to install DynamIP as an NT Service are available here.