Windows 10: Black screen with white horizontal line flashing on top left

Guys please help my laptop was fine yesterday until one day when I opened my laptop it loads then suddenly its just black screen with white horizontal line flashing on top left of the screen. Not sure if this is a hardware issue considering my laptop is brand new and only got this last year. I have comodo firewall so it cant be a virus unless it is one. I didn't make any changes on my laptop before this happened, there were no new updates for my laptop from windows. I'm using windows 10, 1050 gtx nvidia, i7 intel core. I also did a sfc/ scannow and it came out with Windows Resource Protection did not find any integrity violations. I also checked my device manager and all my drivers are up to date. My laptop didn't do this before. And then I hold down the power button to turn it off and when I tried to boot my laptop again it loaded properly and fine this time. I'm not sure if I shouldn't have done that that's why I'm asking for help in this forums to hopefully solve that problem. I'm not a tech expert and i don't know how to dismantle my laptop with a screwdriver and I certainly don't want to reformat again because I just did that a few months ago this year. Please help.

:)

 

Black line (horizontal) on the screen

i used to have windows 7 on my laptop, now I have upgraded it to windows 10. Few days back,i installed steam and a one dimensional horizontal black line about the length of a finger has appeared on the screen, almost an inch below the top left corner of
the screen. uinstalled steam, line hasn't disappeared. what should I do.

 

Black line (horizontal) on the screen

Thanks for replying, actually the problem is a black single horizontal line, not a black screen.

 

Thin Flashing White Line

Hi everyone, I have recently updated my computer. I dont know much about it computers other than they do what I need them to do. After the update i have this very thin white line at the top of my screen the flashes as it pleases with no rhyme or reason.
It is usually in the top center but is occasionally in the upper left hand corner. My computer is the hp pavilion 15 and it had windows 8 when I got it but this summer I got windows 10. This mysterious white line is my only complaint.