touchpad not working, ubunt hangs after sometime on playing videos and using heavy software like netbeans, eclipse, etc

My Touchpad Not Working and Ubuntu get hang after sometime if i play videos on firefox or vlc media player.

I am using Asus X541U Laptop.

I came across different site and tried different approaches.
putting `xinput` in my terminal doesn't show any bus for touchpad.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: linux-image-3.19.0-25-generic 3.19.0-25.26~14.04.1 [modified: boot/vmlinuz-3.19.0-25-generic]
ProcVersionSignature: Ubuntu 3.19.0-25.26~14.04.1-generic 3.19.8-ckt2
Uname: Linux 3.19.0-25-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.23
Architecture: amd64
CurrentDesktop: Unity
Date: Fri Jun 2 11:59:56 2017
InstallationDate: Installed on 2017-04-15 (47 days ago)
InstallationMedia: Ubuntu 14.04.3 LTS "Trusty Tahr" - Beta amd64 (20150805)
SourcePackage: linux-lts-vivid
UpgradeStatus: No upgrade log present (probably fresh install)