HI, I'm new so forgive me if I am a bit stupid. I have a Macbook 2007 and have just put a new hard drive in it. It is formatted journaled etc but the I try and install the OS I get so far, i.e. 2 or 3 minutes in and the screen starts to flip between blue and a lighter shade of blue when the gear wheel stops turning. This is just a loop that goes on and on. What is likely the problem and how can I install the OS on this new drive? Can anybody help?? Thanks. ps maybe this has been covered already but I can't find it.