Hi again,
I have recently ported my VB6 SCADA app onto 3 new computers at a customer. This problem occurred on a Lenovo PC. I use a combination of Ethernet comms and Rs232 for older Honeywell recorders. On this PC the comms get a 8002 error to say the comms port isn't there. A quick test using an old Hyperterminal app with a loop-back show the port working. The new PC has a Rs232 port fitted as comm 1, and I tried a new USB/RS232 converter with the same 8002. The same software works on Win8 and Win XP and also on another PC with Win10.

Any ideas? Sam in lock-down in South Africa.