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How to Change COM Port Assigned to Modem on Your Computer

In many Modem related troubleshooting guides we provide the step release or change the COM port number assigned to the modem. Instead of repeating the same steps in multiple guides, it is better write a supporting article for our other network troubleshooting guides. In this tutorial we give step by step instructions to release or change the COM Port assigned to the modem on your computer.

Steps to Release COM Port Assigned to Modem

  1. Go to Device Manager. To do this follow the steps provided in the link below.

    How to Access Device Manager
  2. Double Click on Modem listed in Device Manager
  3. Click on Advance Tab in Modem Properties Window
  4. Click on Advanced Port Settings
  5. Change COM Port Number: Click on the drop down menu near COM Port Number to do this. If an even number is (eg: 2) is assigned to your modem, make sure the new value too an even number (eg: 4, 6 etc). If the already assigned COM Port Number is odd number (eg: 1, 3 etc), make sure the new value to an odd number.

    It is important, never change an odd number with an even number while changing the COM Port Number.
  6. Restart Computer

After reboot your computer will assign the new COM Port Number assigned to modem. Just like release COM Port Number, you can reset Winsock on your computer. To perform this follow the steps provided in the link below.
How to Reset Windows Socket on Your Computer

After releasing and assigning new COM Port Number for your modem, you may be anxious to check the Internet speed you are getting. Following link tells how to check it using various tools.
Tools to Check Internet Connection Speed you Are Getting


Amit said…
Worked like charm..
Thanks a lot :)
Admin said…
Thanks for your comment.
Anonymous said…
Thank u so much. It works!!! Amazing great!!!
Unknown said…
A million thanks for the valuable info posted. Error 633 was pain. Changing com ports did the trick. Thanks a ton.