I was trying to Linux  Mint from live-usb and made a stupid mistake.I created master boot record and my HDD partition become unallocated.After rebooting from live OS, I'm unable to get to boot menu.http://www.linux-mag.com/s/i/articles/7875/Figure2.jpgIs there any way to recover all my data? Right now I can only boot to live-usb.
gparted partition master boot record corrupt
partition;gparted
First, to avoid messing up, you should backup an entire image of the disk (provided you have a bigger disk to store it). For this, several solutions are proposed on this question, last time i did it, I used dd. Once you are sure you can restore the image in case of problem, you can use testdisk to redetect the partition table and fix it.This question for instance provides a solution.