How can I find out the COM number of a serial device?

Question

today I had to configure an Ethernet Switch (AT-8000GS/48) via serial console to turn on stacking mode and so on. I used a RJ45 to Serial-9-Pin to USB adaptor.

First, I tried to use PuTTY under Windows 7. After selecting Serial Connection it asks for the device name like COM1 and a speed. A colleague told me the speed, but I had no idea how to find out the device name. Device Manager only says "Serial USB Adaptor".

Finally I booted up Ubuntu and connected via PuTTY, because dmesg told the new device name.

TL;DR

How can I find out the name of the serial port on Windows?

Solution

1. Go to Device Manager
2. Click Ports
3. Find your Serial USB Adapter in the list
4. Right click the device, and click Properties

5. Go to Port Settings, then Advanced

6. Here, you should have a drop down box where you can choose the COM port.

Some instructions for this with pictures can be found here.

Comments

[Hendrik]

There is no Ports-Tab... prntscr.com/a1079g It seems, Windows doesn't even recognize the device correctly

[Jonno]

@Hendrik Yep, you're missing some drivers there. Can you double click it, go to Details and in the drop down click Hardware IDs, then post the information in the first line so we can establish the driver it needs?

[Hendrik]

Oh man, now it started to install the drivers automatically. I think the reason is, that I had no internet connection in the switch room...

[Jonno]

@Hendrik Things should be a lot easier to work out from here then :)

[Hendrik]

Thanks for your time ;) It shows as COM3