USB or serial interface, if serial is serial port on laptop or using USB to serial cable. I had no luck with USB/Serial convertor. I remember setting up an ELO on W10 using the serial interface and if I remember correctly I had to use the Windows 8 Drivers on the system, Unfortunately it is buried in the shed somewhere so not simple for me to dig out. Make sure to uninstall any existing versions.
Also you can try installing the software in W7 compatibility mode. It has been a couple of years since I last messed about with it all
