How to Use Touchpad and keyboard at same Time

A-0-A!

   I am using Window 10 Pro on Dell intel core i7. I am getting problem in playing games because when i press "w" to move my player forward and also try to control my camera then the touchpad does not work. What is the problem? I searched it a lot on Youtube and Google but all in vain. 

   Mostly people say that i should go to Settings>Devices>touchpad>Additional Setting> and then Goto the tab Device Setting.

 The Device setting tab is not showing in my Laptop.

Please Help me for solving this Problem. Sorry for my weak English. Thanks in advance