How to Build a PC That Runs Windows Mac

1. Follow the instructions over at the OSx86 Project. This site hosts a community of computer enthusiasts who build systems that can run both Mac OS and Windows. There are also instructions on how to install Mac OS on a Windows machine you already own.
2. Use MacApper's guide, titled 'DIY Hackintosh Tutorial: Build a Mac Pro for Cheap.' This guide lays out every detail for you, telling you what kind of hardware you should buy and how to get it all working. When your machine is complete, you can install Windows using Apple's Boot Camp software and have a machine that runs both Windows and Mac OS.
3. Visit the Maximum PC site and use the guide titled, 'How to Build Your Own Hackintosh.' This process lays out the finer points of building a PC that can run both Mac OS and Windows by letting you know which processor to buy, which motherboard is compatible and what other components you'll need to complete the task.