I was trying to install Zend Server CE on my computer but when I got to the point were I need to choose the port for my Web Server it says: "Web Server Port: 80 Occupied". So I decided to check what is using Port 80 with CMD by typing: "netstat -o -n -a | findstr 0.0:80":


I check for PID:4 in Task Manager's Processes and Services. Seems PID 4 is "System".

So, what I want to know is how can I stop "System" (PID:4) from using Port 80?

INFO: I am using: Windows 7 64bit; Zend Server CE 5.5.0

  • Wouldn't hurt to telnet a "GET / HTTP/1.1" to and see what comes up. – LawrenceC Oct 30 '11 at 3:18
  • @ultrasawblade How exactly do I do that? – apokaliptis Oct 30 '11 at 3:28
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    Run telnet 80 and then past that line in and press enter twice. If you're running Windows 7, you need to install telnet client from "add and remove Windows features" first. – billc.cn Oct 30 '11 at 22:35
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    World Wide Web Publishing service in Windows 8 64 for me did the trick. – user187014 Jan 10 '13 at 19:17
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    HTTP service state can help you to identify the running services in case of PID 4. Run netsh http show servicestate and look at registered URLs or Logging information. – pazadev Jun 13 '16 at 15:44

Ok, after searching the web for a while I found a solution to my problem.

Just follow these steps to diagnose and resolve your issue:

  1. Get pid that is listening port 80: netstat -nao | find ":80"

  2. Open task manager, go to processes tab and check “PID” in Menu/View/Select Columns…, then look for the process using the PID found in last step.

  3. If it is a normal application or IIS, disable it or uninstall. Some programs (such as Skype) have the option to disable its use of port 80.

  4. If it is a System Process—PID 4—you need to disable the HTTP.sys driver which is started on demand by another service, such as Windows Remote Management or Print Spooler on Windows 7 or 2008.

    There is two ways to disable it but the first one is safer:


    • Go to device manager, select “show hidden devices” from menu/view, go to “Non-Plug and Play Driver”/HTTP, double click it to disable it (or set it to manual, some services depended on it).

    • Reboot and use netstat -nao | find ":80" to check if 80 is still used.


    • Launch RegEdit.

    • Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\HTTP

    • Change the value of "start" to 4, which means disabled.

    • Reboot your computer.

My solution was step 4.

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    Where is the "Non-Plug and Play Driver" tree in the device manager of Windows Server 2012? – Maria Ines Parnisari Dec 21 '14 at 19:16
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    The device manager approach isn't available from Windows 8 onwards. – Roddy Aug 28 '15 at 8:27
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    The registry solution worked on Win8. I miss Linux. – AlikElzin-kilaka Sep 4 '15 at 18:13
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    Please tweak this a little bit. Disabling the "HTTP" service in Windows disables all of it's dependencies. The specific service using port 80 is "W3SVC" (The World Wide Web Publishing Service), a dependency of "HTTP". This can be verified by running "net stop W3SVC" from an Administrative Command Prompt, and then 'netstat -n -o -a | find ":80"' to verify nothing is listing on port 80 anymore. I recommend disabling the World Wide Web Publishing Service (W3SVC) instead (if you don't want to disable SSDP, the Print Spooler, HomeGroup, and Function Discovery). – chriv May 3 '16 at 19:32
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    I don't understand this instruction at all Go to device manager, select “show hidden devices” from menu/view, go to “Non-Plug and Play Driver”/HTTP, double click it to disable it (or set it to manual, some services depended on it). There is no Non-Plug and Play Driver”/HTTP menu item anywhere. – Martin Erlic Apr 13 '17 at 8:42

I just had this issue after installing Windows 8 Pro - Build 9200. I tried several methods but couldn't get any of them to work. This one, however, fixed it.

You need to change the binded IP address for HTTP.SYS

netsh http add iplisten ipaddress=::


  • This solution is great, when you need to both run a server that does not use http.sys, and one that does. – Thor Jacobsen Feb 11 '13 at 21:29
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    Also worked for me. What does it actually do though? – akame Sep 10 '15 at 20:44
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    I thought this fixed my issue because it did free up the port but it also had some other side effects. Specifically, I was unable to bind to specific hostnames via IIS after this change. To undo I used netsh http delete iplisten ipaddress=:: – cchamberlain Mar 7 '16 at 1:52
  • This worked for me, but had side effects. Please see my answer below for a possible alternative that uses the same command, but a different IP address. – Dave Morton Apr 24 '17 at 16:56

On my case it was WebMatrix. See possible solutions (including this one) here: http://www.sitepoint.com/unblock-port-80-on-windows-run-apache/


Open Services from Administrative Tools and locate “Web Deployment Agent Service”. Stop the service and set it’s startup type to “Manual”.

The Web Deployment Agent Service is deployed with WebMatrix and was the cause of my woes. It may also be distributed with other applications installed using Microsoft’s Web Platform Installer.

  • Also the problem I was having (on Windows 10) – toby1kenobi Oct 18 '16 at 10:57

PID 4 is hard coded to be the "System" process which is part of the system kernel.

If the port is occupied by the system, you probably had IIS enabled. See https://stackoverflow.com/questions/1430141/port-80-is-being-used-by-system-pid-4-what-is-that

  • I have uninstalled IIS 7.5 Express thinking that would help. Maybe I have to restart? I am going to try that. – apokaliptis Oct 30 '11 at 3:05
  • Nope. Problem still persists. – apokaliptis Oct 30 '11 at 3:19
  • Do you have IIS 7.0 (the one shipped with Windows 7) installed as well? Normally if you just stop w3svc, the port will be closed. – billc.cn Oct 30 '11 at 13:34
  • Nope. And as far as I know, I shouldn't have any other webservers installed either. – apokaliptis Oct 30 '11 at 20:52
  • Could you run netstat again but only post the ports that are LISTENING? – billc.cn Oct 30 '11 at 21:12

While using the command netsh http add iplisten ipaddress=:: did, indeed, allow Apache to start on my Windows 10 64 bit system, it wreaked havoc with trying to access localhost, as that was bound to :: instead of, even with the proper entry in my hosts file. What I ended up doing was to use this command instead: netsh http add iplisten ipaddress= This not only worked, but allowed browser access to localhost as well. For me this was a superior solution.

  • While you method didn't work for me (I still get a 404 page from an unknown web server running locally) it did make me try to go to which works as a workaround as long as you remember it – Anders Sandberg Nordbø Jan 7 '20 at 17:19
  • Just found out, if you tried to add :: you need to delete :: as well, then it will work with localhost as you described – Anders Sandberg Nordbø Jan 7 '20 at 17:21

Open the Services list Find "World Wide Web Publishing Service" Stop it, and set it to Manual

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