Question: * I have encountered a weird error while setting up the `FTP` for my Windows Server 2008 R2.
* After finishing the setting up of the FTP, I tried starting it, as it was `OFF` by default whereas I think it should be started by default.

![After setting up FTP](https://i.stack.imgur.com/HNnnD.png)

* On trying to start this FTP, I encountered an error saying "FTP cannot be started. Another FTP site may be using the same port".

![On trying to start the FTP](https://i.stack.imgur.com/mrrH9.png)

* As there is not another FTP site other than this one, I can't figure it out.
* I tried `netstat -a`, and found out that the port number **21 is already listening**, but I **don't see** any FTP site running on my `IIS console`.

![enter image description here](https://i.stack.imgur.com/gM3XY.png)

* Can anyone please help me out as to how to resolve this problem or at least let me know how to stop the service which is listening at port 21 so it stops listening. Then I can set this current FTP site to listen on port 21.

Answer: 
Restarting the windows service "Microsoft FTP Service" does the trick for me on Windows 10. 

[![enter image description here](https://i.stack.imgur.com/Vy2Ws.png)](https://i.stack.imgur.com/Vy2Ws.png)

Original Source:

<http://clintboessen.blogspot.com/2013/03/the-ftp-site-cannot-be-started-another.html?_sm_au_=iVV766VqSV6HNtVN>
Please make sure that the socket pooling is enabled for your ftp site.

* Fire up "IIS console"
* goto your "FTP Site"
* look for "advanced settings"
* in connections, "disable socket pooling"
* set it to "false"(default)

I got the same error when i turned off socket pooling.