Function keys on the Fujitsu laptop sometimes get "stuck on," or you may accidentally press keys that disable their functionality. When this happens, you must reset the function keys. You must troubleshoot and reset the keyboard by unlocking keys and rebooting the computer. When you reset function keys, the keys' functionality returns to the original setup.
Toggle the "Function Lock" key. The "Function Lock" key is labeled "Fn." This key is similar to the "Caps Lock" key, and may be affecting the performance of your laptop. Press the key and try using the function keys again.
Reboot the computer. If you accidentally set a sticky key or the keyboard drivers have crashed, the function keys reset when you reboot the Fujitsu computer.
Reinstall the drivers if the keys do not reset when you reboot. To reinstall drivers, click the Windows "Start" button and type "device manager" in the search text box. Press "Enter." Click the arrow next to Keyboards. Right-click the Fujitsu keyboard icon and select Remove. After the device is removed, click Action, then click "Scan for hardware changes." Windows will then reinstall the device drivers.