Hi Thank you for the reply, and yes I have already tried what you suggested, but unfortunately when I go and click onto SET LANES button this stops the COM port start up. I have also tried to run this on my lap top(which does not have any serial ports, only USB) just in case the PC I use on my slot car timing was at fault. The message (top left of screen) when this is used says COM 2, COM 3 or any number selected as an invalid port number, so it would appear that the program is not replicating USB ports as serial COM ports. Any other ideas to get this sorted would be appreciated - Thanks Chris