I am installing Ubuntu 13.04 on a computer that has Windows 7 already installed. I do not want to wipe it, so I took space from it, and made a new partition. I am doing this from a disk image that I burned this morning. All is fine up to this point. I then clicked the "Install Now" button. A dialog box popped up, saying the following: "No root file system is defined. Please select correct this from the partition menu."
What is going on? What am I doing wrong? What should I do to fix this?