Network administrators typically use DHCP servers to assign IP addresses on local networks. Some users modify their IP addresses without permission, which can create problems on the network. You can edit the registry to prevent users from modifying their IP addresses.
Start regedt32 and navigate to the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces registry subkey. From the menu bar, select Security, Permissions. Clear the Allow inheritable permissions from parent to propagate to this object check box. In the Security dialog box that opens, click Remove to remove the inherited permissions. Then, click Add in the Permissions for Interfaces window. In the Select Users or Groups window that opens, select Everyone and click Add. Finally, click OK in the Permissions for Interfaces window. Now every user on the machine is prevented from modifying network settings.
As a network administrator, you can use Group Policy to apply this registry subkey's permissions to all the machines on your network. Then, all the machines on your network will prevent users from modifying their network settings. Some advanced users might still find a way to change their IP addresses, but doing so is complicated and therefore unlikely.