Cannot Boot/Go into Desktop (Black Screen)

So I am having this problem.

1. When I switch on the laptop, Windows starts up and until the choice to select the user account. After that the desktop doesn't show, just black screen.

2. Next I try to switch off the laptop to restart again, the lights on the laptop corresponding to charging, boot etc are on, but now it shows just black screen not even showing the loading bar for Windows.

This happens for numerous times, and after long hours (probably 12 hours to a day) when I startup again, number "1" happens and number "2" follows.

I was once able to start into safe mode (after waiting the long hours period) and now the desktop is being shown after entering into a user account. But after another restart it doesn't even show the start screen to press f2 to boot into safe mode, just black screen.

Today I restarted again and after selecting a user account, I could see the desktop being minimized and everywhere else black screen. I tried to boot again and number "2" happens. It's going to take some time before I can boot into safe mode itself.

Could someone be kind enough to help me?