You can do this by flipping a switch in your BIOS.
First, before you do this, BE WARNED. Messing in your BIOS can be hazadous, and it can TURN YOUR COMPUTER INTO A EXPENSIVE PAPERWEIGHT.
Warning aside, heres how I did it.
First, I booted into the BIOS. Shutdown the computer, and then get into the BIOS. To do that on a HP 2000 Notebook, hit Esc before GRUB loads - might take a few tries to get it to work.

sorry for the blacked out stuff, figured it'd be better if I kept my laptops serial number and related info private
Then, select the System Configuration
tab. Navigating the BIOS menu is normally done with the arrow keys, but read the instructions for your machines specifics.
Then, select the Action Keys mode
toggle. Turn them to DISABLED
.


Save your changes, and then reboot.

Now that you've got it working, you can do the same things (volume, brightness etc) by using the keyboard shortcut fn + F key