Last Thursday the internal hard drive of my iMac (see signature for system specs) failed to boot after I turned off the computer while accidentally booting onto an external hard drive rather than booting onto the iMac. FYI I was running Mavericks on an external HD and Mountain Lion on the iMac. Anyway when I try to boot on the internal HD I get a grey screen, a spinning wheel and progress bar which takes 10 mins to fill, and then the iMac shuts down. Disk Utility confirms that the internal HD cannot be repaired. Fortunately I have a Time Machine backup of all my data. My external HD is partitioned: one is for Time Machine and the other is a small partition for Mavericks. I've contacted a mac repairman and will get the mac's hard drive replaced this Tuesday. As a temporary stopgap I booted into the Recovery 10.8 disk, wiped the Mavericks partition on the external HD, downloaded and installed 10.8.5, and then restored my data from the latest Time Machine backup point. Everything seems to be running fine BUT... I noticed a bunch of folders dotted around replaced with aliases or shortcuts which leads to either the Lost+Found folder on the Time Machine partition (which wasn't there before and contains 4636 items @ 574.75GB!) or to the original file/folder on a prior Time Machine backup point. Subsequently I have erased, reinstalled and restored ML again and replicated the same issue. Not only is it a pain but it concerns me that when I get the iMac's HD replaced and restored via Time Machine I will replicate the same problem of aliased folders on my system. Could it be that my Time Machine backups are damaged? Despite the internal HD being unrepairable I am still able to access all files and folders on it and it appears intact. I investigated creating an image of the Macintosh HD via Disk Utility but I'm not sure if it's the right course of action. For example, could I create an image of the original Macintosh HD and then restore my iMac with it? Or will it possibly copy any faults with the hard drive that prevents it from booting properly? Suggestions? Can someone shed further light on my problem and put forward suggestions on rectifying it? Please help because I'm lost and I have no idea what to do next. My sincere thanks in advance.