Hello I installed Ubuntu Gnome 14.04LTS then after installation I found out that my Graphics Card is disabled. Why? Im on a hybrid machine with IntelCore i3 and AMD RADEON Graphics card. Thank you in advance.
Your graphics card is not disabled. Rather you are on Generic Xorg Display drivers. You need to install the proprietary AMD drivers to be able to use your AMD Graphics card.
You can search for
additional drivers in applications. And enable the drivers suitable for your Graphics cards. And if the Drivers support hybrid configuation, you should be freely able to switch between your Intel HD and Radeon chipsets.
If the above method doesn't let you control the hybrid configuration, Ubuntu Documentation has a manual way of installing drivers in order to control the hybrid chipset.