So have an old MacBook from 2010ish. Starts getting a bit slow so took it to an apple store. They suggested that the hard dirive might be corrupted. I decided to buy a bigger hdd and double the ram. I installed it all myself as it was out of warranty. I'd made a time machine back up of my old Hdd. Went to boot it up and got the folder with a question mark icon flashing, obviously due to the blank hard drive. From reading some threads on here, turned out I required the installation CD to boot up. Inserted disc 1, the folder with question mark dissappears and... Nothing, just a blank grey screen. Tried it several times now with holding c and option etc., still the same... Have I missed something???