Why is System process listening on Port 80?

Question

I am running Windows 7 RC1. I have multiple issues getting IIS to work on my system and today when I installed a new application and I tried to load it using http:\localhost\MyApplication I get absolutely no errors and I get no page load. Just a pretty, white blank page.

I did some digging and I found something about some other process listening on port 80 so I did a scan using netstat -aon | findstr 0.0:80 and discovered that PID 4 was listening on that port.

PID 4 does not show in task manager so I fired up Process Explorer and it showed me that PID 4 is the System process. (Multiple google searches seems to indicate that System always uses PID 4).

Since then I am basically stuck. I have no idea why System needs port 80 and what to do about it.

If you google the following strings you will find two helpful Experts-Exchange articles at the top of the search results and you can read them for some helpful information.

(If I gave the direct URL to the pages then Experts-Exchange would ask you to pay...but when you click on the results from a google search you can scroll all of the way to the bottom to read the exchanges.)

Here are the google searches...
"System Process is listening on port 80 (Vista)"
"SYSTEM Process is listening on Port 80 and Preventing IIS Default Website from Running"

The last entry from the first result showed how to do a trace of http.sys at the following URL:

http://blogs.msdn.com/wndp/archive/2007/01/18/event-tracing-in-http-sys-part-1-capturing-a-trace.aspx

Trace showed nothing useful. Any thoughts?

Answer 1

This post on Getting Apache to run on port 80 on Windows 7 (internet archive) describes your point.

It seems the 'http.sys' (Windows Remote Management?) service is enabled by default in Windows 7.
Run through the comments on that link for some more notes...

_{the hypen-site does not necessarily have the only answers.}

Answer 2

'Web Deployment Agent Service' runs on port 80 as System. You might have this running if you are using WebMatrix.

Answer 3

Open Services.msc and stop this service "Sql server reporting services(MSSQLSERVER)"

I had tried EVERYTHING, but that worked for me:

further instructions on how to stop that service are below

1. Right click on My Computer
2. Select Manage
3. Double click Services and Applications
4. Then double click Services
5. Right click on "Sql server reporting services(MSSQLSERVER)"
6. Select Stop ...and voila, port 80 was released

Answer 4

You can stop the HTTP service temporarily from the command line:

1. Run an administrator command prompt (e.g. Start, search for cmd, right click on it, choose "Run as administrator", approve the UAC prompt if any.)
2. Type net stop HTTP
3. If there are other running services that depend on the HTTP service, you'll get a list; double check to see if there's anything listed there you can't bear to do without. Or, if you're just stopping HTTP to use port 80 temporarily, make a note of those dependent services that you'll want to restart once you're done with the port. Either way, if it's okay, enter y to continue.
4. Some dependent services might throw up stop control warnings that cancel the operation; just repeat net stop HTTP until it is stopped (i.e. until it says The HTTP service was stopped successfully.)
5. Later on, you can restart any of the dependent services, using net start or by using the Services item in Administrative Tools, and the HTTP service will be started again automatically.

Answer 5

telnet localhost 80 returns HttpAPI/2.0 which in turn means to "Sql server reporting service". Stopping the same releases port 80.

Answer 6

Take ProcessExplorer, run it, open TCP/IP properties of every process (service), find process (service) that listening to http (80) port and switch it off.

I found Autodesk EDM Server was listening to http (80) port.