How to Identify Ports in Use on a Computer

There are two different kinds of ports in use on your computer at any given time--physical ports and network ports. Sometimes, when your computer gives you an error message, you may wish to find out exactly which ports are in use and which resources are using them.

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Discovering Which Input/Output Ports Are in Use

Step

Click "Start" then "Control Panel." Navigate to "Device Manager." In XP you click the "System" icon then the "Hardware" tab.

Step

Select the "View" drop-down menu then select "Resources by type."

Step

Click on "Input-Output Devices" to see a list of the ports in use.

Identifying Network Ports In Use

Step

Open a command prompt by clicking "Start" and typing "cmd" in the "Run" box.

Step

Type "cd /" to get to your C: drive.

Step

Type "netstat -a" to see a list of all active port connections. If you wish to see more data or see the data displayed differently, typing "netstat a" will give you a menu of possible commands you can use and their results.