I wonder how i should do to play music on my xbox360 by my pc. i have connect the xbox to my router but my xbox can't find my pc. i havent any ide on how i should do. please help me

There are a couple ways. This guide is on xbox.com: Xbox.com | System Use - Use a PC with Xbox 360

You can either network your 360 to a Windows PC and stream music from the PC or rip CD's directly to the 360 HDD through the dash menu. Both require having a 360 HDD, you can not stream music or rip music to the 360 without a 360 Hard Drive. Here's a guide for ripping audio CD's to the 360.

Ripping Audio CD's to Xbox 360 and Loading Custom Soundtracks In-Game

Here's a guide for setting up a network with a Windows PC:

Xbox.com | System Use - Use a PC with Xbox 360

__________________