does your stereo support radio? If so enable file sharing on your windows 7 pc. Then the contents (music) will automatically appear on your n900 (thats how it worked for me). Then you have to set the fm-transmitter to broadcast on a ccertain frequency and tune your stereo to tha frequency. In my opinion if your stereo has a 3.5mm audio jack and your wireless router is close to it you might be able to hook up your n 900 directly to your stereo for bete quality and less static


these simple steps should help you

1)go to start>control panel>internet and networking >home group>enable sharing
2)share all your folders
3)connect your n900 on your wifi network and open media player
4)hopefully you will see on the left down corner your pc
5)click on that and stream your music
6)enable your fm transmiter and try to find a frequency with static
7)tune your stereo system on that frequency and there you have it