The scariest computer component failure....the PSU most definitely. When a PSU goes, it usually makes a loud gun sound and is occasionally accompanied by smoke and fire. That's some scary stuff let me tell ya. You're just sitting at the computer minding your own business when you hear this whining sound. Just as you think "What he heck is that sound?", the screen goes dead and you think the world is coming to an end and the feds are after ya.
It's only happened to me a couple of times, but in mere seconds my heartbeat increases to like 150 bpm. It's almost as scary as being shot at. It sure sounds the same and you know you have to do something before the computer burns your house down. That's why I recommend to everyone that they have a fire extinguisher near their computer (the ones made for electrical fires). Sure the chances of that happening to you are slim, but if it does you wanna be ready.
EDIT: Oh and for software, there's no comparison:
A long time ago back when viruses were new, there was a mastermind. He created this malicious program that could actually destroy hardware. It could thrash your hard drive so it would cut itself up. It could wipe your CMOS and BIOS in an instant. It destroyed any floppy disk you put into the drive.
I can't say too much about this piece of software due to a hacker oath I maintain, but you don't have to worry about it anymore. It's been eradicated. To this day, no one has created a piece of software that could do what this thing could. I certainly don't know how it's even possible. It's main fault was the fact that it destroyed computers. Because of this, it didn't transfer itself to other computers most of the time. Therefore, there was only a handful of computers infected at any given time.
Some theorize that the creator was in control of this virus; that what it did was impossible for a program to do. On the other hand, there are others who insist this guy knew things about programming that others didn't.....that he had a gift that could of helped the world. Instead he decided to do what he did. His main motives are still unclear. Perhaps he did something to the world of computers that isn't known. Perhaps something is forever written into windows that was his own creation. Maybe he got hired on my Microsoft. Some think that the virus stopped affecting computers because he died. Whatever the case, it's gone now and I'm very glad for it.
