I installed a new 500GB HDD with 7200 RPM (Or whatever its called). I startet the mac and a question mark comes up. I really don't know what to do. Please tell me! And I've read over the internet and I got another mac to connect it too (iMac) and I got the two discs that I got when I bought a MAc Mini one year ago. Btw, I have the MacBook Aluminium Unibody! EDIT: I tried to put my old HDD in the macbook and it worked. But not the new.