When I start my computer, windows 7 boots up as it would usually do before I installed ubuntu. So, it is not giving me an option to boot ubuntu instead of windows. I have Windows 7 Professional 64-bit installed and just installed the 64-bit version of Ubuntu 13.04.
When installing Ubuntu on computers in the past, it provides a boot selection menu to select which OS to boot. In my case, it goes straight into booting windows.
I've tried going into the f12 boot menu but there is nothing helpful to select.
SOLUTION: Found this page on the Ubuntu site. https://help.ubuntu.com/community/Boot-Repair It involves using Boot-Repair as was also suggested below.