#1 is by and far the cause I see when people ask me 'why did thing break?!'

There's a lot of 'Well, I edited the registry and then deleted these two files and installed this 3rd party software so that it looks like it did in Windows XP!' floating in my circles, which almost entirely correlates to the people who are mad that their install is, yet again, broken/not working as expected/having weird problems.

Of course, people are doing this because Microsoft can't stop shitting up Windows in a way that annoys people, and thus leading them to do things that maybe aren't the best idea.

So, in summary: it's a land of contrasts, but stop adding bullshit nobody wants Microsoft.