Sorry if this is a newbie question but I was unable to find an answer through Google. Is it possible to wipe Windows off a Dell desktop and install Mac OS on it? Or is it possible to build a Mac computer and if so, what requirements would you need?
Ok, first of all, it is TECHNICALLY possible for you to install OS X on a non-Apple machine. The problem is like MHC said, it is a violation of Apple's EULA and you wouldn't be legally allowed to install it.
The only people who are sanctioned to run OS X on a PC are Mac developers, and even that is strictly limited as they are given developer boxes by Apple rather than making their own machines.
Another issue you may face is the fact that it's a total pain to install OS X on a non-Apple computer. If you wanted to build the computer from scratch, you would have a very narrow list of parts you could choose from to ensure 100% compatibility. Even then, there are several other issues to consider.
So you can essentially say goodbye to the notion of installing OS X on a Dell computer.