Question Why has this strange problem happened?

[RadonValo]

Hello. My pc was working perfectly fine until I woke up today and found out a strange problem, my pc wouldn't make it through the loading dots at the beginning of the boot. It took me long enough to realise that it is actually on the lock screen(where you enter the user password) but it will just show me a black loading screen. So i did click enter, and then entered my password and enter again, and i entered my desktop after a long time. When i'm on the desktop the pc is so laggy that it will just stay frozen for a few seconds, and then basically give a black screen again.
I am assuming this is a problem caused by the power supply, but im not even sure if it is a softwaral or hardwaral problem. but it is so strange that i decided to ask it on here and I would appreciate any useful answers. <3

 

[kanewolf]

Hello. My pc was working perfectly fine until I woke up today and found out a strange problem, my pc wouldn't make it through the loading dots at the beginning of the boot. It took me long enough to realise that it is actually on the lock screen(where you enter the user password) but it will just show me a black loading screen. So i did click enter, and then entered my password and enter again, and i entered my desktop after a long time. When i'm on the desktop the pc is so laggy that it will just stay frozen for a few seconds, and then basically give a black screen again.
I am assuming this is a problem caused by the power supply, but im not even sure if it is a softwaral or hardwaral problem. but it is so strange that i decided to ask it on here and I would appreciate any useful answers. <3

Failing disk drive is the first most obvious possibility.
What are the specs of the PC in question (CPU, RAM, disks, motherboard) ?