When Eazylink2 uses a Serial Port or a USB - Serial connector, check that the latests drivers have been correctly installed before running the program. With desktop Operating Systems being updated, USB drivers that used to work, may not work after updating the operating system. A disk with the manual and drivers which are normally supplied with the converter, can be years out of date. You are advised to read the manual to see which driver it uses. Use Google to search for the latest driver. Some operating systems will automatically find the latest's driver it requires when the USB Adapter is used - e.g. Windows 8.1