Fn key on keyboard seemed stuck

Try holding down the fn key and then pressing the f11 key.

Never ran into this problem myself but a friend of mine has. He said what fixed his what holding Fn + Num Lock and it remedied his problem.
Unless your key is stuck/broken you can also try a can of air and try to blow it out and or pull the key and make sure its not stuck down.
But deff try the holding Fn + Num Lock method first.

have a look at ur keyboard,,,while holding the fn key press the appropriate function key,,these are the f keys across the top of ur keyboard,,look for the picture of ur keyboard or a padlock

In the lower left hand corner of your Dell Keyboard -- you will see a Blue Key labeled -- "Fn". This key allows you the use of ALL of the other blue labeled keys on your keyboard. You must press the FN key and the other "blue" key at the same time for them to work.

The keys on the right side of the keyboard with the blue numbers on them are controlled by the Numlock key and Fn key. The light at the top of the keyboard near the power button, with the number "9" inside a picture of a lock, will be lit if the Numlock is enabled.
You may need to press the Fn key to type numbers even if the Numlock is turned on. There is a setting in the BIOS called Enable Keypad and if you set it to By Numlock you will not have to hold down this key to type a number.

If you are still having trouble with these keys, please see the general keyboard troubleshooting guide

http://ftp1.us.dell.com/diags/R65848.htm#Key not responding or typing wrong character

Use air compressed can to clean under and around key (if issue could be mechanical)

Sounds like you need the keyboard replaced...

The Dell has a "Fn" key. The "Fn" used with other keys control special features. I have a Dell keyboard here, on it holding the "Fn" and pressing "End" will alternately mute/unmute the speakers. "Fn" + "Page up" will raise volume, "Fn" + "Page down" will lower. You may have the volume muted, or turned all the way down.
The keyboard I have is from an 1100, your "Fn" key combinations may vary from mine.

Hello,

You've activated Euro mode. This is toggled by pressing holding the Fn key plus an Fkey that has an icon in the same color as the lettering on the Fn key that looks like the Euro symbol. Press the Fn key plus the Euro key to toggle out of Euro mode.

Regards,
Worldvet

Make sure Num Lock is on (the light belonging to numlock is on).
Then use Fn + Keys with a blue number on it to use the keypad.
Make sure you hold the fn-key, for each number you want to type...
If this doesn't work, try Fn + Esc. If your laptop goes to standby mode, The Function key is allright, and there is another problem. If it does not work, your keyboard may not be installed probably, or may be defect.
Please post some feedback,

Good luck

I think it is not the Fn key but the NumLock that is activated. Look for the key labeled NumLk , this is the number lock. Also check if the light on the notbook with a number (usually number 1) is on. If it is on, yo must deactivate the numlock by pressing it again. It works in toggle mode. Sometimes the numlock is activated together with the shift key, sometimes with the function key.