If you neither have replaced your device nor made any modification in the configuration of the network you are trying to connect to, it is possible that you are being affected by the automatic security control systems of the UPM. In that case you will be unable to connect to Eduroam. If you think that is your situation please write us an e-mail to gico(at)etsit.upm.es, indicating the MAC address of your device so we can investigate your status.
Eduroam is a network that needs some configuration steps and, depending on the Operating System. Make sure you have followed the instructions detailed in the website provided by UPM 'Servicio de Red Inalámbrica'. To check if your username and password are valid you can try connect to Politécnica Virtual from a wired network.