I'm inserting my buddy in here as I've never killed a PC.
I've built all my friend's computers. Then there's 1 friend who just doesn't take care of anything he owns. I'm in Madison, he's in Rockford. I'm on my way out to him to install something new, I don't remember what it even was. 20 minutes out he calls me, his computer is on fire. Literally. I'm like dude what the hell I'm 20 minutes away what were you even doing?! Idiot saw his floppy drive power wasn't plugged in because I never bothered, no use for him (winxp days). So what does he do? Tries plugging it into the fan pins on the motherboard. Guess what happens when you plug two things in together that are providing power. Fire, fire happens. I get there, half the motherboard is melted and his room smells like electronic death, and he did it while his computer was on and running.
So much for installing whatever new hardware it was.
I called him an idiot, he bought pizza and wings for wasting my time lol.
To this day, been building computers for almost 16 years and that's the one of two computers that was killed by the hands of the user. The other one was eh. Friend's brother had autism pretty bad. He graduated highschool and he loved gaming on computers, that was his thing. Nothing else mattered so his parents gave me a credit card and told me to get whatever it was I needed. Get it all up and running, he's happier than hell. Week later my friend tells me he spilled a 2 liter of mountain dew on the computer and all the soda went into it from the top fan cut outs lol. RIP. Moutain Dew super charges us buddy, not computers