This article describes how to reserve a range of ephemeral ports on a computer that is running Microsoft Windows Server 2003, Microsoft Windows XP Professional or Microsoft Windows 2000. In some situations, you may want to reserve a range of ports so that a program or process that requests a random port will not be assigned a port that is in the reserved range. When you reserve a range of ports, only a program or process that specifically requests a port that is in the reserved range can use the port.
Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:
322756 How to back up and restore the registry in Windows
To reserve a range of ports so that only a program or process that specifically requests a port that is in the reserved range can use the port, follow these steps.
Windows Server 2003 or Windows XP Professional
Start Registry Editor (Regedit.exe).
Locate and then click the following registry subkey: