Gandi,
You must connect to the Tenor directly using a standard serial cable and setting hyperterminal for 38400, N, 8, 1, No flow control. Then reset the Tenor and hit enter to modify the parameters (when you are given the 3 seconds to do so). The last question will be to reset to factory default and you need to say Yes. This will erase the entire config including your password, but not the Ip address, subnet or default gateway.