If you have an Nokia Music Unlimited subscription on your Nokia Music account, you should be able to download music from Nokia Music for free. If you are being asked to purchase tracks, please check the following:
If you are still unable to download free music, for example if you cannot find your username or you do not have the option to register the PC, contact Nokia Care and make sure to include the IMEI number of your Nokia Music Unlimited (Ovi Music Unlimited or Comes With Music) device. To get the IMEI number, press *#06# on you mobile device. You will then find the IMEI number (a k a Serial number) displayed on the screen.