I don't think the original poster understands anything about Windows/MAC/Linux or Operating systems in general, as fistfury alluded to, so heres a run down of why this is rather silly, and what you should do.
You can't by mac as an add on to a PC, Apple keep their brand separate from PC's (windows or linux = PC), despite any hardware similarities, and they like it that way.
Snow Leopard is an upgrade for Leopard users and requires a Mac with an Intel processor.
You can't magically change the hardware of a PC into the hardware of a MAC, this job is
hard, you may need different components, allot of software changes and a fair amount of pirated material, knowing apples way of restraining OSX to MAC's.
You would have to reformat your disks, whipping all of the data on them, in order to convert them to the NTFS file system. (I believe it's NTFS anyway, I forget.)
What you should do is get windows 7 or linux, I'd recommend Fedora or Mint or Ubuntu, as far as linux goes for a first timer, in any case your reformatting your disks at a bare minimum.
Last edited by Vox; Jul 26, 2010 at 07:56 AM.