Nope, you would have to buy a Mac PC to do that, for some reason, and I have no idea why, it is illegal to put it on your own built computers. I am not saying it can't be done, but its not legal and I would not recommend it.
and btw i mainly want to build a computer so i can have what i want in it...i mostly do video editing and thats why i wanted to go mac, but now that i cant, i need advice from you guys, what system should i go with and what processor? my budget is around 750 and i already have the tower.