Great Todd. That is just what I'm looking for. It makes sense that it would keep track. I have two different ftdi chips that I'm using so I can see how it got messed up. Dwight
________________________________ From: cctalk <cctalk-boun...@classiccmp.org> on behalf of Todd Goodman via cctalk <cctalk@classiccmp.org> Sent: Tuesday, November 20, 2018 5:43 AM To: cctalk@classiccmp.org Subject: Re: What is windoes doing? On 11/19/2018 11:34 AM, dwight via cctalk wrote: > 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 > Windows "remembers" com ports of USB devices based on the VID/PID of the USB device. This allows the same device (USB com port) to get the same COM assignment but means you end up with a ton of useless COM port reservations when you're using a large number of different USB COM devices. Something like https://superuser.com/questions/408976/how-do-i-clean-up-com-ports-in-use has instructions for removing them in Windows 7. I could have sworn I just uninstalled them from Device Manager but I forget now as it was a while ago. Todd
