One of the biggest complains people have about Lenovo W540 is the behavior of the Function keys.
For all those people who upgraded from Lenovo W520 or W530 the most important feature everyone missed was the function keys on the laptop i.e F1 to F12. By default the function keys are not accessible by directly pressing them and user has to first press the Fn key + the Function key.

Well if you want the old behavior back then there is a simple way, there is a feature in Lenovo W540 to enable the previous behavior again.
Just follow the below steps:

1. Just Press Fn Key + Escape Key

2. Wait until the small LED in the Fn key turns green and bingo!! you are all set.

Just check out the below Video incase anything is not clear.

The Fn key will be enabled by default just like Lenovo W520 or W530. This behavior is persistent even after you restart your Laptop. This was a great relief for me as I was very much used to Fn key being enabled by default.