How to make sure that a certain Port is not occupied by any other process

Question

You can use "netstat" to check whether a port is available or not.

Use the netstat -anp | find "port number" command to find whether a port is occupied by an another process or not. If it is occupied by an another process, it will show the process id of that process.

You have to put : before port number to get the actual output

Ex netstat -anp | find ":8080"

It's netstat -ano|findstr port no

Result would show process id in last column

netstat -ano|find ":port_no" will give you the list.
a: Displays all connections and listening ports.
n: Displays addresses and port numbers in numerical form.
o: Displays the owning process ID associated with each connection .

example : netstat -ano | find ":1900" This gives you the result like this.

UDP    107.109.121.196:1900   *:*                                    1324  
UDP    127.0.0.1:1900         *:*                                    1324  
UDP    [::1]:1900             *:*                                    1324  
UDP    [fe80::8db8:d9cc:12a8:2262%13]:1900  *:*                      1324

It's (Get-NetTCPConnection -LocalPort "port no.").OwningProcess

If you prefer Powershell, use this. You will get the name of the process.

PS C:\Users\Administrator> Get-Process -Id (Get-NetTCPConnection -LocalPort 9093).OwningProcess

Handles  NPM(K)    PM(K)      WS(K)     CPU(s)     Id  SI ProcessName
-------  ------    -----      -----     ------     --  -- -----------
   6021    1464  2760976    2131548     290.39  25512   2 java

The PID is in Id column, and it provides process name, as well.

If no process is using this port, you get a red error message.

If you want to kill the process with PID 25512, use

taskkill /PID 25512 /F

/F means force, some processes cannot be killed without /F