Can I run Mac OS X on a custom built or non-Apple Commercial PC?

The license agreement forbids doing this. Even if it were possible, given the nature of this forum's terms of use, you won't find discussion on how to permit it.

Should you find such discussion on this board, it is likely to be removed by the moderators as soon as it is discovered. http://www.apple.com/legal/ gives you the resources to report such instances where you feel the law was broken.

Numerous crossplatform solutions exist for reading PC file formats on Macs, which you are welcome to ask about on the forum, and when those don't suffice, this tip explains how to run Windows on a Mac: https://discussions.apple.com/docs/DOC-2741