Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I am trying to learn the maximum number of serial ports that can be configured on Windows 7. Any information on this will be greatly appreciated. I'm having trouble finding this.

share|improve this question

migrated from Oct 31 '12 at 1:37

This question came from our site for system and network administrators.

How many do you really need? – Zoredache Oct 30 '12 at 17:05
We need to connect around 80 devices. – Rob Oct 30 '12 at 17:26
What kind of devices? Perhaps RS485 would be a better alternative. – Chris S Oct 30 '12 at 17:27
Unfortunately I am locked in to RS-232 due to hardware limitations. We are planning to proxy the serial port via Ethernet using third-party hardware. We are in the planning stages and I couldn't find the maximum number of ports I could configure. – Rob Oct 30 '12 at 17:32
up vote 3 down vote accepted

Windows 6.0+ support 256 Communications Port devices.

share|improve this answer
Thank you for the information. That's more than we'll need. Where did you get this information? I will need a reference in my documentation. – Rob Oct 30 '12 at 17:36
Honestly I don't know where or if MS has this documented. It's a definitely the current limit however. – Chris S Oct 30 '12 at 19:27
Windows has supported 256 ports since Windows 95, at least according to the API documentation. – John Gardeniers Oct 30 '12 at 19:31
@JohnGardeniers I think that's only for 32-bit apps; IIRC 16-bit are limited to 9... Do you have a link to something official looking? I couldn't find anything. – Chris S Oct 30 '12 at 20:53
You may be right. I don't have any references to hand but recall that I looked up the information when I was writing a comms program for Win95, which was obviously a few years ago. – John Gardeniers Oct 30 '12 at 23:08

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.