HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
Description
Determines the highest port number TCP can assign when an application requests an available user port from the system. Typically, ephemeral ports (those used briefly) are allocated to port numbers 1024 through 5000.
Windows 2000 does not add this entry to the registry. You can add it by editing the registry or by using a program that edits the registry.