Hi big geof. I have used a broadband modem on an older computer than yours with a known USB problem, and it installed with no difficulty, so I don't think the age of your computer is the cause of this difficulty. As both lights are on your modem is getting power and is synchronising to the remote server. You say that the system tray indicates that the modem isn't plugged in. Presumably you have tried to sonnect to your ISP without success. My only guess is that there is a problem with the modem itself.