My Mac Mini experienced a HDD failure last weekend. Unfortunately I had no backup whatsoever. I bought it second hand without the restore discs. I do have a functional boot disc and thumb drive of OSX Lion, however, when I start the mini, and hold "C" or "alt" I get nothing no boot menus, just a gray screen with a flashing folder and question mark. Where do I go from here? I've also tried "cmd+alt+shift+del". Is there a way to get this to work?