I had the same question and I found this page. And the answer is in @zipzit's comment. So I post it as answer here:

To see "Com Ports" in Device Manager in Windows 10 you should select "Show hidden devices" in View menu.

You can still do that in Windows 10:

• Run Start > Device Manager

• Double-click the type of device to configure, for example "Ports (COM & LPT)"

• Right-click the device to configure and select Properties

• Select the Resources tab

• Click to clear "Use automatic settings" (it's unavailable and appears dimmed for devices for which there are no settings to configure or are controlled by Plug and Play)

• In "Settings based on" select the hardware configuration to modify, for example "Basic configuration 0000"

• In "Resource settings", select the resource to modify, for example "IRQ"

• Click "Change Setting"

• In "Edit Resource" type the new value and then OK

• Repeat the above for all the resource settings that you want to modify

• Quit Device Manager and reboot.

In the command prompt use

mode

Used without parameters, mode displays all the controllable attributes of the CON (console) and the available COM devices (and LPT as well).

Accepts /? switch for basic help:

mode /?