But also if you boot from the install DVD or CD what ever you are using you can bring up a terminal and type
the "-l" is a lower (L) not at number one. That command will show you your partitions and your hard drives look for the one that has an asterisk (*) and has the flag to boot
In my case /dev/sda1 had all the partition with the OS installed and /dev/sdb1 had the boot partition
/dev/sda1 being the first hard drive and /dev/sdb1 being the second hard drive. I did the changes in BIOS and everything went well after that.