Hi, I was trying to install Windows 7 onto my machine and now it appears that the hard disk is ruined. Instead of the Apple logo during startup there is a question mark that flashes. I was told by the Apple people that it was a hard disk problem and that it now needs replacing. The DVD drive in the iMac has not been working for a while now. I'm currently contemplating how to go about fixing this. I do have an external blu ray player from which I should be able to boot but I don't know how. Can someone please tell me how I can fix this problem? I currently have a non functional iMac. If I open up the Imac and replace the HDD will the problem fix itself? Will the iMac want to re-install OS X?