I have OSX running on my PC, there's no reason that OS X can't run on a pc, since Apple made the switch to intel processors all the components are identical to any other pc. But to protect their bottom line i guess, and to not have to spend money developing drivers for a plethora of different hardware, they've bios locked the software to only run on their devices.
But there are ways around that.
The closer your pc is though, to the components to a mac, the easier it is to get it installed. There's a whole community called @ osx86.org and insanelymac.
This has been going on for @ least 4 years or so.