top of page

Serial Com Port

How to determine what service is using a serial com port

     If your telephone system sends call records over a serial connection then these instructions can help you see what computer service is using a serial port.  These instructions are used in cases where you think you have a free com port, but when you try to open the com port you receive an error that states that the com port is already in use.  If you do not know what program has the com port open, you can use these instructions to locate the service that is using the port.


  1. Go to Device Manager

  2. Select PORTS - Com & LPT

  3. Right click on the com port in question

  4. Select properties

  5. Select details

  6. Select SERVICE from the drop down list

  7. You will see the name of the service that has the com port open

Comm One Call Accounting Software

Technical Support

PO Box 759 | 1390 E Meadow Valley Dr

Draper, UT  84020

(800) 771-9182

FAQ-1446 Determine which serial port a service is using

Posted: 02/02/2017

Updated: 02/13/2021

Author: Comm One Technical Support

bottom of page