My MacBook starts up to a black screen, and continues to fill with text (things turning on). It came installed with Snow Leopard. I upgraded the RAM (while on Snow Leopard.) I some how broke the HDD and replaced it with a HDD from my brother's old and useless Mac. The OS was downgraded to Leopard. I finally got a (torrented version, I am not paying for another disc that they should have given me!). Anyways, when I try to upgrade the OS this is how it goes. -- Click here to install OS. -- Enter password. -- Click okay to restart. -- Goes to black screen (shuts everything off.) -- Turns to white screen. -- Goes to black screen very quickly. (I don't see the rotating icon or apple image anymore on the white screen) -- Turns on. -- Asks me to login. -- No changes to the OS. Please help!