I had 3 partitions on my late 2011 MBP internal harddrive: Mac HD (about 700 gb), Windows (about 30 gb) and temp(about 20 gb). Temp was for transporting filed from my mac to my windows. Anyway, I discovered that my temp was in a wrong format because I could'nt put my 5 gb file on it. So i went to Disk Utility and Erased temp, putting it in ExFat. It threw somekind of error, MediaKit was mentioned. Anyway, I didn't have an idea what to do with the error so I just went ahead and tried to copy my file on the partition. I left the room for some time to let the transfer finish. As I came back, my computer was at Windows booting screen, with the white little thingy blinking in the corner. I waited for some time but the boot-up wouldn't countinue. So I restarted and looked at my partitions on which to boot on. Only windows appeared there. I tried to fix my windows booting with my win 7 disc, it said that some kind of error occured and it couldn't be done. Then I went into recovery mode. Disk Utility shows that I have only 1 partition on my mac - temp. And it is 750 gb, with about 10 gb taken by the files i was transferring to it while this all began. I am willing to make a clean install, but I'd really like to get some important files from my Mac HD. It isn't possible that the mac parition (which had about 400 gb worth of data on it) just dissapeared when my computer probably crashed? As my bootup screen shows Windows, then I have some hope that my mac and windows are somewhere on this hard drive, somewhere hidden. What to do, how to do it? I've been trying to google on this but it is not a very common situation to get in. I'd be very grateful for any kind of advice on what to do. I have a macbook air to use while trying to fix my pro if that could help me in any way.