Dns records are not dynamically updating
By default, all computers register records based on their full computer name.
For Windows 2000 computers, the primary full computer name, a fully qualified domain name (FQDN), is based on the following system settings: The Primary DNS suffix of this computer appended to the Computer name.
Windows 2000 provides client and server support for use of dynamic updates, as described in RFC 2136.
For DNS servers, the DNS service allows dynamic update to be enabled or disabled on a per-zone basis at each server configured to load either a standard primary or directory-integrated zone.
On the next page, under the Hostname Information window, you will see a location to change the IP address.
Replace the IP address being shown with the IP address you received from Port Check Tool and click Update Host at the bottom right of the page.
The DHCP Client service performs this function for all network connections used on the system, including connections not configured to use DHCP.You will see a list of domains/hostnames that are associated with your account.Next, to the hostname, you will see the IP address that we are currently resolving to.To manually update the hostname, login to your No-IP account and click Hosts/Redirects at the top left of the page.Next to the hostname that you need to update click “Modify”.
By default, client computers running under any version of Windows 2000 dynamically update their host (A) resource records (RRs) in DNS when configured for TCP/IP.