You can use the NETSTAT command to quickly see all the used and listening ports on your computer. Note it is not a complete substitute for a port scanning tool. If you’d like to have your computer remotely scanned for open ports use our Security Scan instead.
To see a list of listening ports, open Command Prompt and type:
C:\> netstat -an |find /i “listening”
You can change “listening” to “established” to see what ports your computer actually communicates with.
In Windos XP and Win2k3 Server you can use the -O switch with the NETSTAT command to also get a list of all the owning process ID associated with each connection:
C:\> netstat -ao |find /i “listening”
To see all open, closing, established and listening ports, simply use:
You can also make the netstat command refresh periodically by adding a number of seconds at the end, for example, to make it refresh every 5 seconds, use something like:
C:\> netstat -an 5
You can see process identifiers using the following command at the command prompt: tasklist and tasklist /svc