I have Dell Vostro 1434 68 with windows 10 installed. My laptop was working fine untill today. I started the laptop and was using it then it stuck, I pressed the power button to turn it off. When i turned it on dell logo appeared as usual but after that it stuck on black screen with horizontal white blinking lines. I restarted it many times , it still behaves the same. It once loaded a full black screen with the cursor which was not moveable . Can anyone please help? support assist reported "OS_BOOT_FAILURE" then it started  recovering but the issue still exists.