One a side note, an xbox is generally less expensive than a pc. So its cheaper to turn an xbox into a pc, than a pc into an xbox. And by turning a pc into an xbox (even though its IMPOSSIBLE), you would lose all the great features of a pc (i.e. dvd burning, pc gaming, windows, MS office, adobe photoshop, all the coding programs that make applications for the xbox, etc.)
In other words, its a bad idea that wouldn't work. Not the craziest thing ever thought up, but not gonna happen any time soon...err ever.