For reasons too long to explain, I reluctantly removed Ubuntu from my computer. After completely removing it and deleting the partition that it was installed onto, I discovered that I still had two Ubuntu entries in the boot order in my BIOS menu. I deleted them by following the instructions in this answer:
As I was doing it, everything appeared to go smoothly. However, upon reboot one of them came back. What's going on here? How do I delete it permanently?
Here is my boot-info URL: http://paste.ubuntu.com/1372806/
I'll gladly provide any other information that may be needed to diagnose the problem.