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I am using USB-to-Serial port adapter in Windows 7 notebook. The model as seen in Control Panel > Hardware and Sound > Devices and Printers is named as Profilic USB-to-Serial Comm Port. When remove the adapter from USB port and hibernate and then wake-up and reinsert the adapter it keeps changing between COM3 and COM4. I am always using the same USB port. Just now, for example, it is COM3 and advanced properties for the device allows changing the port setting but it says COM4 is "in use".)

I am using PuTTY as my terminal program. If I guess or remember the COM port number incorrectly I need to restart PuTTY. It is also burdensome to do the mouse clicking circus to get the port number before starting PuTTY session. The state of my work-flow makes me feel like an idiot.

Question: Is there a way to lock the COM port in automated fashion (without needing to click click click all over the places with the mouse) so that when I reinsert the USB-to-serial port adapter, the port selection is always the same?

Work-around My plan B is to have two identical PuTTY sessions except for the COM number; run a short cut to a script that in some fashion detects which port number is valid and run PuTTY with that session (command line option -load <session-name>). However, I would like to find more general solution in case I want to access the serial port in some other ways (using some other application).

Related (unanswered), almost duplicate question (hardware configuration different, these two questions might have a little bit different answers): USB hub assigning random com ports when Windows 7 PC or USB Hub are rebooted

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