I didnt say anything about C or F12. The link I provided indicated that you use Esc and F1. I was only refering to the fact that if you have more than one account on your computer, you have to make sure that you are logged in as administrator to give you any access for changes.
On my laptop, when I hold the F2 key in (different than yours) it takes me to the bios setup screen.
There is a menu along the top which reads:
Main Advanced Security Others Boot Exit
You use the right arrow to pan over to boot which will have a list like:
Your computer before any changes is set to boot from your harddrive. If you wish another devices to be booted from when you next turn on your PC or reboot, you would select whichever device you want