The com port number on my Windows PC seems to get out of control, as Windows increases it as every time I plug in a new USB com device. Is there any way to reset the number?

Answer

There is an registry key - "ComDB". You can find it in - HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\COM Name Arbiter. 1) Right click that key, and select "Modify". 2) In value Data section select all and delete reset to Zero ?0?. Once you restart the computer, all coms are free.You will need to reinstall on all com port devices. It is always good to do back up of the registry before deleting any entry from registry, and we are not liable to any damage to your computer.