Installed new compatible 1TB WD HD on late 2009 iMac. I noticed that even w/ HD out, there were 2 items always present; disk2, OS X Install ESD and disk3, OS X Base System. They were even there when no HD was in iMac. I can only boot w/ flash drive that has mavericks and utilities on it. Cannot boot into Safe Mode, Single user mode works as does accessing recovery tools. I can access disk utility. HD erased and formatted, verified, repair finds no problems, permissions options are greyed out. When OS X Installer is up, it says Install OS X w/ the green to blue X in a circle. It begins, 24 minutes remaining....gets to 23 minutes remaining and yellow triangle w/ exclamation point appears; Install Failed, the OS X upgrade couldn't be started because the disk is damaged and can't be repaired; erase your disk and try installing again (I have nothing to back up since I originally erased and reformatted the new HD). I restart and the process repeats. I've been working on this for a week and appreciate assistance, thanks.