Predator G3610 - Why isn't my KB36211 keyboard shortcut not working?

Mehhh

Hi,
I own a Predator G3610 with a keyboard model KB36211 with its shortcut keys such as disable volume, increase volume, decrease volume, e-mail, desktop, etc.
Now these keys are disabled. I remember using Avira System Speedup and after a scan and the "upgrades" the keys stopped working. I deleted this program and cleaned the HDD with Windows cleaner.
Now I would like to know how I can recover these shortcut keys.
I searched to come back to the previous parameters and even after using Windows to restaure the previous versions of the HDD it didn't work. 

Any help is welcome. Thank you already. 

Commodore_1995#

does this model have a function called function key behavior in the bios? Have you tried to install acer quick access?