My brother bought a dell inspiron 15 5559 laptop from USA for me i reside here in India.The specs are intel i7 6th gen 8gb ram ddr3 amd radeon r5 m335 4gb ddr3 graphic card.I installed cs go it was working smooth on maxed settings so installed cod mw1 on maxed settings it lagged a bit. So i searched the internet for solution there it said to update the driver.I went on amd site installed a driver for my windows i dont remember but i might have uninstalled the preinstalled driver.The new driver from amd site was of no use instead it was lagging more so i uninstalled it and went on dell site to get a gc driver for my model.It was just like the preinstalled one but it had some difference.I played cs go and cod mw1 on low graphic but it was lagging slightly which is strange because before doing all this experiments on my laptop it was smooth. So i unistalled the driver from dell site and restored my laptop.I got the same driver as before with some difference again.And the games are still lagging.I think the preinstalled driver is lost how can i get it back?And also how to know that whether i am running a game on intel graphics or amd graphics.