I had ubuntu 13.04 and I updated it to 14.04 which faced me to much many problems. So after a while I decided to come back to 13.04. During the new installation it alarmed me that there is another OS (ubuntu 14.04) and I chose a the first choice (to delete it and install new OS). Now, after installation, I can't find my old partitions, as if the whole hard disk is integrated. Does it mean that all of my data in hard disk has deleted? or maybe there is a way to mount the former drives?