Hi I bought a new MacBook just before Christmas and up until a few weeks back it has been fine. About a day after the latest Leopard update, my macbook froze and hasnt been able to boot since. All it showed was the Apple logo and the spinning gear and would not boot into Leopard. I left it for about an hour once, and it just kept spinning, and nothing. I tried shift I think it was to get into safe mode and it wouldnt. So I dug out my boot CD's, (It came installed with tiger, but came with the Leopard update disc) and tried to install Leopard again, which failed. So I then tried to install Tiger in the hope of later upgrading back to Leopard, and about half way through the install I got a message saying " there were errors installing the software". So is there anyway I can go about totally cleaning the HDD and installing OS X from scratch? Im very new to Mac and any help would be appriecated. Thanks in advance.