It certainly happened to you that, when you connect a new USB device to your Windows PC, the operating system assigns the device a COM port with a high number because of the previous ones are in use:
Windows indeed keeps the COM port reserved even if the device is not physically connected to the computer. You can clear some old reservations with the following steps:
– run a command prompt as administrator:
– type the following commands:
set devmgr_show_nonpresent_devices=1 start devmgmt.msc
– choose View – Show hidden devices:
– you can now remove (uninstall) old devices and free the associated COM ports: