Question: When I am starting rails server using `rails s` command it is showing `A server is already running. Check C:/Sites/folder/Pids/Server.pids`

When I open the file it is outputting a 4 digit number only so how could I resolve this issue ? 

**FYI**

1. No other instance of Rails cmd is running this time.
2. Checked Task manager but only `cmd.exe` is showing no else process is running. (using Windows).

Answer: 
```
lsof -wni tcp:3000

```

Then you should see the ruby process and you can run

```
kill -9 processid

```

you should be good to run the process now

```
rails s thin

```

running multiple processes doesn't seem like a good idea and from what i've read many people agree. I've noticed many memory leaks with rails unfortunately so I couldn't imagine having two processes running. I know with one overtime my page refreshes increasingly become slower because of the data being stored on memory.
You can get rid of the process by killing it:

```
kill -9 $(lsof -i tcp:3000 -t)

```