Port 80 is being used by SYSTEM (PID 4), what is that?

Question

I am trying to use port 80 for my application server, but when I perform netstat -aon I get:

TCP 0.0.0.0:80 0.0.0.0:0 LISTENING 4

When I look up the process in task manager, it shows PID 4 is SYSTEM , that's it. No extension... nothing. Just " SYSTEM ". What's going on here?

I'm afraid to end this process, what do I do?

Answer 1

There are many services, which can listen port 80 on windows.

Luckily you can detect and stop them all running simple console command:

NET stop HTTP

When you'll start it, you will get list first:

To avoid this problem in future go to Local Services and disable listed services .

NB - Some services will restart themselves immediately, just run 'NET stop HTTP' few times .

Answer 2

一个名为“Web 部署代理服务”(MsDepSvc) 的新服务也可以触发 PID=4 的“系统”监听端口 80。

Answer 3

Also, try stopping "SQL Server Reporting Services (MSSQLSERVER)", that apparently defaults to 80. I did that and port 80 freed up. PID identified the culprit as "System", but apparently that System can mean multiple things.

Answer 4

I had the same problem. Could fix it by stopping the World Wide Web Publishing Service under running services.

Answer 5

the IP adress is 0.0.0.0, state = LISTENING: means that port 80 is listening to all interfaces (not used)

How to read NETSTAT -AN results:

• https://sites.google.com/site/xiangyangsite/home/technical-tips/linux-unix/networks-related-commands-on-linux/how-to-read-netstat--an-results

Answer 6

This works for me:

1. Right click on My Computer .
2. Select Manage .
3. Double click Services and Applications .
4. Then double click Services .
5. Right click on " World Wide Web Publishing Service ".
6. Select Stop .

Answer 7

It sounds like IIS is listening to port 80 for HTTP requests.

Try stopping IIS by going into Control Panel/Administrative Tools/Internet Information Services, right-clicking on Default Web Site, and click on the Stop option in the popup menu, and see if the listener on port 80 has cleared.

Answer 8

Working solution - tested on Windows 10

There are many reasons for this, the one cause/solution I recommended is this:

Open Command line as Administrator, then:

1. stop http service

net stop http /y

2. configure 'http' service to be disable by default

sc config http start=disabled

If above solution does not work, find your specific case - here

Restart your web server/XAMPP/Apache and you're done.

---

To re-enable http service

use

sc config HTTP start= demand

the source of explanation is here

https://web.archive.org/web/20190917190806/http://servicedefaults.com/10/http/

Answer 9

I've found out that "SQL Server Reporting Services (MSSQLSERVER)" starts automatically and listens on port 80.

I hope this helps.

O

Answer 10

This can be very easily fixed by following these five steps:

1. Open Services
2. Right click on World Wide Web Publishing Service
3. Click STOP

To prevent this issue in future :

4. Go to Properties
5. Change Startup type to Manual

Viola u are good to go !

For more info on root cause: https://serverfault.com/questions/65717/port-80-is-being-used-by-system-pid-4-what-is-that

Answer 11

An other service that could occupied the port 80 is BranchCache

services.msc showing it as "BranchCache"

or use the net command to stop the service like

net stop PeerDistSvc

Update:

PeerDistSvc is a service behind svhost.exe, to view svchost services type

tasklist /svc /fi "imagename eq svchost.exe"

Answer 12

The issue is how to free it up, simply use

net stop http

https://stackoverflow.com/a/16243333/777982

Answer 13

I knew these answers were right , but my services.msc was not showing the services, however this did the trick:

sc stop "MsDepSvc" 
sc config "MsDepSvc" start= disabled 

Answer 14

I just got this problem today, since it showed up after Norton requested reboot I blamed Norton.
But it wasn't Norton, I removed Norton, rebooted -> problem still there.

netstat -nao was showing that PID 4 owned my port 80 connection.

I then went to control panel, then "Turn Windows features on or off" then unchecked Internet Information Services.
Rebooted, the problem went away.
My xampp server is running ok now.

I don't ever remembering turning IIS on in the first place. I had been running many months before this happened. I still don't know what caused it in the first place. Maybe a previous windows updated enabled iis and my reboot turned it on, I don't know.

Answer 15

This Process works for me:

1. Right click on My Computer.
2. Select Manage.
3. Double click Services and Applications.
4. Then double-click Services.
5. Right click on "World Wide Web Publishing Service".
6. Select Stop
7. Restart XAMPP

Answer 16

Identify the process programmatically

All the answers to date have required the user to do something interactive. This is how you find the PID when netstat shows you PID 4, without needing to open some GUI or handle a dialogue about depending services.

$Uri = "http://127.0.0.1:8989"    # for example


# Shows processes that have registered URLs with HTTP.sys
$QueueText = netsh http show servicestate view=requestq verbose=yes | Out-String

# Break into text chunks; discard the header
$Queues    = $QueueText -split '(?<=\n)(?=Request queue name)' | Select-Object -Skip 1

# Find the chunk for the request queue listening on your URI
$Queue     = @($Queues) -match [regex]::Escape($Uri -replace '/$')


if ($Queue.Count -eq 1)
{
    # Will be null if could not pick out exactly one PID
    $ProcessId = [string]$Queue -replace '(?s).*Process IDs:\s+' -replace '(?s)\s.*' -as [int]

    if ($ProcessId)
    {
        Write-Verbose "Identified process $ProcessId as the HTTP listener. Killing..."
        Stop-Process -Id $ProcessId -Confirm
    }
}

That really busted my chops. I hate HttpListener and wish I'd just used Pode.

Answer 17

netsh http show urlacl

The command is mentioned in a previous comment but I'd like to bring it up as an answer. It will get you all reserved URLs in the system. If you look through all records with "80" in URL, you shall have your answer.

For example, in my case, I got:

Reserved URL: http://+:80/Temporary_Listen_Addresses/
        User: \Everyone
            Listen: Yes
            Delegate: No
            SDDL: D:(A;;GX;;;WD)

Reserved URL: http://+:80/0131501b-d67f-491b-9a40-c4bf27bcb4d4/
        User: NT AUTHORITY\NETWORK SERVICE
            Listen: Yes
            Delegate: No
            SDDL: D:(A;;GX;;;NS)

After a quick Google search, I learnt that "NT AUTHORITY\NETWORK SERVICE" belongs to SQL Server. So I went to Services and stopped SQL Server Reporting Service, port 80 is free again as I check netstat -a -b

Answer 18

On the lastest version of windows this service is called as "World Wide Web Publishing Service" (W3SVC)

C:\Windows\system32\svchost.exe -k iissvcs

You can stop this service by going to Services (services.msc) and stopping the service and then setting the "Startup type" -> Disabled for preventing it from running on windows startup.

Answer 19

对我来说，它在停止 Web 部署代理服务后工作。

Answer 20

I had this same exact problem, except that i have never used IIS. While I was fixing another system bug, I had set the apache service to manual start, hoping to reduce the complexity of my system. After I fixed the other bug, apache wouldn't start. I futzed for a while, but all it took was setting apache back to automatic start: Start > Administrative Tools > Services.

Apparently when Apache starts this way, it claims port 80 before the SYSTEM process can.

hth someone. all my googling turned up the 'can't have IIS and Apache on the same machine.' this is for the other one percent of us.

Answer 21

In case you use Razer product and install Razer Synapse software on your PC, it blocks the port 80 too.

It is not included in the netstat command so I am not able to troubleshoot it. Since there are many services included within the software, I can't analyze which one that blocks the port. After uninstalling the Razer Synapse, I can start the Apache server again on Windows 10.

Answer 22

Try netstat -b, that may hopefully shed some light on the situation (showing what .exe is using the port). Good luck.

Answer 23

这不能解释 PID 方面的事情，但如果你运行 Skype，它出于某种原因喜欢使用端口 80。

Answer 24

In my case, it happened after installing Microsoft Web Matrix. Uninstalling this trash along with "Microsoft Web Deploy" fixed the issue.

Answer 25

None of these worked for me. I had to go to a SuperUser question .

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:

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

This is the one that worked for me!

Answer 26

I was looking around for PID 4 and came to this question. From this answer and a blog post I figured that anything to do with PID 4 is probably a Windows Service, so you may want to look for the relevant services in services.msc .

Also, this process is run by System, which is considered another "logged-on" user.

Answer 27

我遇到了同样的问题，这是因为 IIS 在服务器上运行，如果是这种情况，您可以使用 IIS 管理器停止它。

Answer 28

如果您运行的是 Windows Server 2012 R2，请确保删除工作文件夹：http: //blogs.technet.com/b/filecab/archive/2013/10/15/windows-server-2012-r2-resolving- port-conflict-with-iis-websites-and-work-folders.aspx文件服务器下的删除工作文件夹功能对我有用。

Answer 29

BranchCache was my problem. My resolution was to run Powershell as an administrator and run:

Disable-BC -Force

Reference: https://docs.microsoft.com/en-us/powershell/module/branchcache/disable-bc?view=win10-ps

Answer 30

对我来说，我必须在我的 VM 上卸载“Citrix Virtual Desktop Agent”

Answer 31

PID=4 does not show up in Task Manager even after placing check mark on 'Show processes from all users". Well there is only one user.

However, netstat -b shows multiple connections poiting to the same PID=4 which on this computer displayed the following.

I have only chosen those pertaining to TCP protocol.

This was acquired while trouble shooting IIS which did not start after trying out many others. I do not think you should stop this process.

Answer 32

type netstat -a -n -b -o |more

if stopping World Wide Web Publishing Service helps

then in IIS manager review each site's bindings settings, by selecting a site and on the side panel click on binding. then change port 80 to something else if required.

Answer 33

我停止了万维网发布服务，然后它起作用了。

Answer 34

Also, the "developer portal" (on Windows 10) causes System to listen on a TCP port. Usually ports 50080 and 50443.

Answer 35

我刚刚去服务并停止了 Web 部署代理

Answer 36

在阅读了有关该问题的所有答案并尝试了所有方法后，无济于事，我卸载并重新安装了 XAMPP ，该方法有效。

Answer 37

WINDOWS 11

For me it was the World Wide Web Publishing Service who made System use port 80.

Hope this helps new Win11 users.