Recently I have been needing to restart my computer due to port exhaustion issues. Originally I thought it was a network issue, but upon reading up, I realized the error messages were pointing to port exhaustion.

After looking at netstat -q it is fairly clear what is going on, the Windows System process is bound to every conceivable port, and before you think that is an exhadgeration, when I entered that command, it actually took minutes for the screen to scroll to the bottom...

The PID is 4, which I determined is the System process. Why would this be? These are bound but not active ports, why are they not clearing up? Why are there so many? Very curious.

A data point is that I recently set up a new FreeNAS server, and have 8 SMB shares that I have connected to this laptop. At the time of last exhaustion, however, I was only "connected" to 3, and disconnecting from them did not free any ports.

Any idea what this could be? The System process only has 24kb in memory, I can't imagine what it would possibly be doing with so many bound an inactive ports...

  • Does temporarily disabling the FreeNAS server free up the ports?
    – Steven
    May 19, 2017 at 15:47
  • One possibility is that your system has been compromised. May 19, 2017 at 18:28

1 Answer 1


Use the Process Explorer - Windows Sysinternals to examine the details of the System process.

Specifically, examine the Threads tab for any non Microsoft libraries. The TCP/IP tab may also provide relevant information.

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