Function buttons are not working

[nadeem]

I have my HP laptop,
when i turn on my laptop all button of key pad are working well except Funtion buttons,
i tried to use them with and without funtion key and i also tried trouble shooter no issue found.
help me in this way ..

 

[Bighorn]

Which model HP Notebook/Laptop is involved, how old is it? I actually have a few HP and Dell Notebooks.
One diagnosis I perform in such a situation is to boot to a free Linux LiveDVD or Linux Live USB drive, helps narrow down whether the problem is with the hardware or the OS/Operating System. I prefer Linux Mint but Ubuntu is a good choice.