How can I convert my Xbox 360 game into a PC game?
If you're designing the game, it may be possible to compile the game for Windows instead of Xbox 360; many Xbox 360 games are designed in Visual Studio with the XNA framework, which was designed with this in mind.
If it's a commercial Xbox 360 DVD, you're likely out of luck: You'd need the entire source code (along with assets such as art, 3D models, and audio) to recompile the game for Windows, along with the tools the game studio used.
i think its language problem (XBOX and PC are different system) and to retrieve the rights of the game
You can't just "convert" games from one platform to another especially when they are using completely different architectures (PowerPC vs. x86/64).
Maybe you can find a 360 emulator for your PC which should allow you to play most games on your PC but don't expect any wonders to happen. Emulation takes a lot of processing power and with the 360 having a triple-core processor on its own I would expect a fast Quad Core x86/64 CPU being mandatory to get an acceptable gameplay.