I burned the ubuntu-14.04.1-desktop-amd64.iso to a DVD-R after checking the iso with MD5SUM. From there, I rebooted, entered BIOS to make sure I was booting from the CD-ROM, and entered the Ubuntu install screen. I then selected the Install option, continue, continue, continue, finish, and then I was prompted to remove the DVD and press Enter.
At this point, when I press Enter, the computer boots to Windows after informing me that "Windows did not shut down properly." After that, when I reboot, I am given no option to boot from Ubuntu or from Windows 7 -- instead it boots straight to Windows.
Here's what I'm running..
Operating System: Windows 7 Home Premium 64-bit
System Model: HP Pavilion dv7 Notebook PC
Processor: AMD A6-3400M APU with Radeon(tm) HD Graphics (4 CPUs), ~1.4GHz