Fn keys not working - HEWLETT-PACKARD Hewlett Packard HP G62-343NR NOTEBOOK PC - XH071UAABA

Did the keyboard come with drivers? also check settings in > control panel > regional and language options > language > details.

There is no standard meaning to any Fn +Fx key combinations. It depends on the manufacturer and the laptop model.
Usually the Fn key works in combination with the Function (Fn) keys F1-F12, and maybe ESC.

In my Toshiba, there is an overlaid numeric pad that can be activated by pressing Fn +F11. Once the sequence is pressed the F11 key led remains lit, and the overlay active. Pressing the F11 key restores the normal keyboard. Fn+Num Lock does not do anything.
Please check you laptop's manual to familiarize yourself with the uses of the Fn key on YOUR computer.

try this link
http://en.kioskea.net/forum/affich-16321-fn-key-type-numbers-and-symbols-instead

The function key, labeled "Fn" and located in the lower-left corner of your keyboard, is a useful feature. By pressing "Fn" along with one of the numbered function keys at the top of the keyboard (F1 through F12), you can adjust your screen brightness, enable and disable your touchpad or wireless modem, lock your computer and complete a variety of other tasks. These keys will not work if the "Fn" key is not pressed along with them. While the "Fn" key itself does not turn on and off, there are settings that can make it behave differently, or seem to be disabled.

Click "Start," then "All programs" or "Programs," then "Toshiba." Select "Utilities," then "Accessibility." Place a checkmark in the box to make sure the "Fn" key will work whether you press it simultaneously with the F1 through F12 keys or immediately before pressing those keys. Customize the other options on the screen, then click "OK." Test your "Fn" key. One of the easiest ways to do this is by pressing "Fn" and "Esc" at the same time. This toggles the sound on your computer on and off, and will show a speaker icon on your screen if it works. Press "Fn" and "Num lock" at the same time if the "Fn" key still does not work. Use the "F11" key if your laptop has no "Num Lock" key. Test the "Fn" key again, using the same method as in Step 4. Locate a licensed repair technician if the key still is not working. A hardware issue may be at fault. Hope this helps.

FN (Function Key) that is usually located near the bottom left on the keyboard is not a key that you press by itself to do anything. The FN key works in combination with the (F1 thru F12) and any other key that has the same symbol or color as the FN Key. You have to Press and HOLD the FN key while pressing another key.

If the FN key is Blue and for example your F8 key has a (white F8 on it and a Blue battery icon on it) then to see your battery metor (how much charge it has left) you would Press the FN and hold it then press the F8 key. The F8 that is white does not require you to press the Blue FN.

Sometimes the FN key might have a white square on it, then the keys that work with the FN key will also have a symbol with a white square around it.

FN (Function Key) that is usually located near the bottom left on the keyboard is not a key that you press by itself to do anything. The FN key works in combination with the (F1 thru F12) and any other key that has the same symbol or color as the FN Key. You have to Press and HOLD the FN key while pressing another key.

If the FN key is Blue and for example your F8 key has a (white F8 on it and a Blue battery icon on it) then to see your battery metor (how much charge it has left) you would Press the FN and hold it then press the F8 key. The F8 that is white does not require you to press the Blue FN.

Sometimes the FN key might have a white square on it, then the keys that work with the FN key will also have a symbol with a white square around it.

not really.
fn is a laptop only thing.

not told what fn , feature you need,
but do try usb f1 to F12. alone, see if that works

you FN key is locked try pressing SHIFT + FN together to unlock it.

If this doesnt works try the same using CTRL + FN an ALT + FN keys.

Try holding fn key and hitting scroll lock or num lock to see if that does it. sounds like you have somehow locked your fn key on.