Iendtify Com Port in Use

Device Mgr displays Ports (COM & LPT) with two subs: Communications Pot (COM1) and ECP Printer Port(LPT1). I am not aware that I am using any COM port with a VB Dialer program I wrote recently modified to use TAPI and CallClerk software used to identify CallID and blocking of selected numbers which also is using TAPI. However if I examine the Properties of the Communications Port (COM1) and select the tab Port Settings the Advanced Button shows using the down arrow adjacent to COM Port Number that #3 is “(in use).” I have selected “Uninstall device” under the Communications Port (COM1) which removed that entry but reappears upon rebooting.

I have used used ProcessExplorer (SysInternal) to examine all the open processes but cannot identify. Any suggestions?

Ed
Windows 10, 21H2 Build 19044.1348
Home built two years ago using ASRock H270M Pro4 motherboard and Intel i5 7500 CPU and cannot handle Windows 11