Plz HELP! My MacBook Pro won't boot any more. It froze all of sudden so I turned it off by holding power button but when I restarted it all I can see is the Apple logo and the spinning gear below it. Then, the gear keeps on spinning and eventually the Apple logo is replaced by a circle with a slash(prohibitory sign). My macbook contains 2 partitions(os x lion and windows 8). I'm unable to access disk utility. On holding cmd + R it again shows the prohibitory sign. The same happens when I try to acces the recovery option. Unable to access safe mode by holding shift key. On holding the 'option' key after some time the startup menu appears. So far I've tried: - Reset PRAM - tried single user mode but couldn't write fsck -fy as there wasn't any option to input any command. - Created a bootable flash drive and repaired disk permissions using its disk utility(many problems were found and fixed). - tried installing OS X again from the flash drive but it stuck after some progress. - restored from my time machine backup but still shows the same problem. Any ideas on what I can do to fix this? Please help me.