I have a MacBook Pro 15" Mid-2009 2.53ghz running Lion and I recently tried to install Windows 7 through bootcamp. After rebooting and going through the boot up, it asked for drivers, so when I tried to eject the windows disk, it wouldn't. After finally resorting to holding down the trackpad while booting up, it ejected and showed the error in the title. I've tried holding the option key, zapping the PRAM, accessing disk utility through a key sequence, nothing worked (I even tried booting from my old snow leopard disk). I then plugged my HDD into an external casing and plugged it into another Mac, I deleted the partition. Nothing changed. Same error. I then backed up the drive and formatted it through the other Mac and plugged the blank disk in. SAME ERROR! I then tried to boot from the disk which I backed the original disk on. same error. I now cloned the back up disk to the original disk and am frustrated on what to do. I've tried holdIng option and zapping the pram from an external wireless AND wired keyboard. No cigar. Help appreciated.