Good evening all, I have tried to do a few searches but not finding a solution that I quite understand, so hopefully some here can help me out. When booting up my Macbook Air 2012 I keep getting the grey start up screen with a load of text referring to a panic of some sort (i have attached an image of what I am getting). This only lasts for around 5 seconds and it then switches to another screen (same grey background with apple logo) with text saying that my computer shut down suddenly and to press any key to carry on etc and after doing so, it goes back to the original screen and simply keeps looping between the two. I have tried booted up using the Comd + R combination and launched Disk Utility and when trying to verify the HD, many lines of text in read appear stating 'Missing thread record (id = xxxxxxxx) and I am then told the HD needs repairing. After clicking on Repair Disk, about 2 minutes into it, I am told that Disk Utility can not repair the disk and that it needs reformatting. I then try to reinstall OS X but again, told I can't use the current disk. Is my only option to reformat the disk? If so, is there anyway I can access the data currently on there first? It's mostly backed up, but could do with a quick check, but no worries if not. Restoring from TM backup is not an option right now. Many thanks in advance for any advice offered.