Hi Gordon,
You are using Windows? (the C:\ in the path was the clue), that port path is a *nix (Unix/Linux) or Mac thing (Mac’s run BSD Unix underneath the pretty gui), so Windows port names don’t look like that.
Based on the name of the robot file it looks like it was written for Raspberry Pi, which typically runs a variation of Debian Linux.
Are you using a USB Serial port adaptor or a traditional com port directly on your PC? Either way you’ll need to know the com port number that you want to use and replace /dev/ttyUSB0 with something like COM3 or COM10 or whatever number your com port has.
If you’re not sure how to find the comports this might help → How to check COM ports in Windows 10?
Dave.