Hi Idrees. I'm Greg, an installation specialist and 8 year Windows MVP, here to help you.
Go to the Asus Support Downloads web page for your model here: https://www.asus.com/us/Laptops/ROG-GL502VS/Hel...
Download the VGA driver at the top and install it.
While there look for any other newer drivers to compare with the ones presently installed in your Device Manager reached by right clicking the Start button.. Download and install those, too.
I hope this helps. Feel free to ask back any questions and let us know how it goes. I will keep working with you until it's resolved.