Hi Ethan That is entirely possible. I do think about it when I plug and unplug the USB floppy drive but not usually for the serial. Is there a way to finish them or maybe stick things in so that I can "safely remove" things? Most of the time for serial, I use a FTDI but I do have some older USB to RS232 voltage converters as well. Dwight
________________________________ From: et...@757.org <et...@757.org> Sent: Monday, November 19, 2018 8:41 AM To: dwight; General Discussion: On-Topic and Off-Topic Posts Subject: Re: What is windoes doing? > I have a question. I use the USB port for serial. In my program, I use a > fixed com port. When going to the control panel, I find that I see (in > use) tags on some of the com ports. I'm the only one currently using the > com ports but recently another (in use) showed up, requiring me to > modify my program to use another com port. How does one unuse a com > port? how do I find out what is using it so I can stop it? I'm using > windows 7 professional. Has anyone else had this problem? Dwight Do you unplug the USB to Serial dongle with a terminal program open? - Ethan