When you want forward lookup registrations but not reverse lookup registrations:
1. Open a CMD.EXE window.
2. Use REG.EXE, built into Windows XP and Windows Server 2003, or from the Windows 2000 Support Tools, to type the following command:
REG ADD "HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters" /V DisableReverseAddressRegistrations /T REG_DWORD /F /D 1
3. Shutdown and restart your computer.
NOTE: There is no registry entry to disable PTR resource record registration on individual adapters.