To set a preferred Graphics processor for Alien: Isolation, using Nvidia' Control Panel:
1. Ensure that you have the latest GPU drivers from either your Laptop’s manufacturer’s official website or Nvidia’s website.
2. Right click on the desktop and select ‘NVIDIA Control Panel’ Then click ‘Manage 3D Settings’ (on the left hand side).
3. Once the Manage 3D Settings page has launched, look for ‘AI.exe’ in the drop-down box underneath “1. Select a program to customize” and left-click on it. If it is not listed, either launch Alien: Isolation then return to the 3D Settings menu, or select ‘Add’, then ‘Browse’ and navigate to your Alien: Isolation Steam App folder (commonly “C:\Program Files (x86)\Steam\steamapps\common\Alien: Isolation”) and select AI.exe.
4. Under ‘2. Select the preferred graphics processor for this program’ select the GPU you wish to use to run the game (For the best performance but higher power-consumption, select High-Performance NVIDIA processor).
5. Once you have selected your preference, click ‘Apply’ in the bottom right corner to confirm & apply..
Also please connect your AC power cable to your laptop.
Some laptop computers will not run with the second more powerful discrete graphics card unless connected to the mains AC.