well when asking other people for help it would help us if we knew what your modem/router was - ie. what model is it and is it connected via usb etc.
if you have any other usb devices connected try unplugging them, such as scanners etc. as I've had conflicts before when trying to get a speedtouch usb adsl modem working when a scanner was causing the conflict... the lights were green also then went back to orange.
so try unplugging any other usb devices to see if they are what is causing the problem.
also, depending on your modem there may be a switch on the side of it or underneath, try flicking that to the opposite of what it is already. good luck