screen brightness function keys not working on windows 8.1

[coombrh]

I have a Lenovo laptop that I purchased with Windows 8. I recently upgraded to 8.1 and now the function key to adjust brightness does not affect brightness. I went into the power settings and made sure the slider on the brightness level was at its highest level. Cannot seem to figure out why my screen is so dark

 

[noidea_77]

You may need to re-install the Fn-key utility. Goto the Lenovo support site and search for newest version for your model.