Why do blue screens occur?

[jeffreycao1998]

I just got a blue screen on my computer and I have no idea why it happened. Does anyone know why this occurs? Also how can prevent another one from happening? I also want to add that i couldn't get a protector like kaspersky for a few days so i might've gotten some bad things.

 

[manofchalk]

Really, for just about any reason your machine could BSOD. You can look up the error code to get a more exact idea of what caused your Blue Screen, but even that will probably lead to a cryptic answer which wont get you far.
The most common causes are a failing HDD or a corrupted install of Windows, but as I said there are plenty of other things that could be causing it.