In my case, there is an F8 button. I used it the first time and it worked but not the second time, there's nothing showing up when I press the buttons, just a black screen.

I have a Lenovo All In One who has been useless because of this problem for over three years, I stumble with this page and decided to try the first option and it worked at a 100%, but suddenly, when I was looking the option to completely erase the archives of my computer, just out of curiosity, I clicked this option where Windows looks for updates and the whole screen shutted down and got back to the same state it was at the start, black screen but the computer turned on with no response of the screen at all, I’m trying the same method but it’s not working. Help please.