Windows 10: Black Lines on the bottom of my screen when switching from 60hz to 300hz

I have black horizontal lines on the bottom of my screen , this happens when I switch from 60hz to 300hz , its very frustrating and shows on top of everything . Is there anyway to fix this? heres a picture of it :

:)

 

Line on the bottom of my screen when switching from 144hz to 60hz

I'm getting a horizontal line on the bottom of my screen when switching from 144hz to 60hz. The line is very annoying and shows up in games and when browsing the internet. Is there anyway to fix this? It doesn't show up on 144hz refresh rate.

Heres how it looks.

imgur.com

 

Black horizontal lines appearing across laptop screen

Took delivery of a brand new laptop yesterday with the following specs:

Unpacked it, started using it, only to find black horizontal lines appearing across the screen sporadically. I updated all drivers, downloaded and installed all Windows updates but to no avail. Screenshots:

First screenshot





Second screenshot





Third screenshot





Some points to note:

• I had the laptop connected to the TV screen and the lines appeared on
  the TV as well, thus suggesting it's not a screen issue.
  
• Because it's a sporadic and somewhat rare event, I can't say whether
  the lines appear during a particular operation/screen or
  anytime/anywhere.
  

I've done a bit of poking around on the net and found that usually the culprit is the graphics card, but not sure. Any suggestions?

 

Black screen error

Hello,

There are several reasons why you are facing a black screen issue. One of these is due to outdated or incorrect device drivers. For us to figure out what's causing this, provide more details by answering the listed questions:

• Can you confirm to us if you are using a laptop or a computer?
• Have you made any recent changes to your device prior to this happening?
• What exactly were you doing when the error occurred?
• Have you tried any troubleshooting steps to resolve this? If yes, specify all of the steps that you have done.

As an initial part of troubleshooting, we suggest following the steps given on this article:

Troubleshoot black screen or blank screen errors. This will help you diagnose and rectify most of the known black screen concerns.

We will wait for your response.