It turns out that humans are to blame for computer crashes. These involuntary shutdowns typically result from glitches in software code written by human programmers.

This code can contain many, many bugs, and these bugs can manifest themselves every now and then to cause program crashes, said Junfeng Yang, professor of computer science at Columbia University.

Software such as Microsoft Word contains code that gives the computer a set of instructions to, say, store data in a certain place. But if one of the memory cells is corrupt (for example, contains a scratch), and the computer doesn't know what to do, it freezes up or crashes.

Imagine if you told a friend (one with the intelligence of a machine) to go to a hardware store to buy fruit.

This guy goes there and finds out there's no such thing there, Yang said. Because it's a machine, it doesn't have the intelligence to do something else, maybe go to a different store to buy it.

Software bugs can also cause problems with a computer's operating system which is the key piece of software that manages the hardware as well as other applications. When the operating system has problems, the entire computer can freeze and crash.

Computer scientists such as Yang are working on ways to catch software bugs before they corrupt your computer.

Similar to, yet much more complicated than, the spell check tools that catch typos and misspellings, bug checkers would automatically find glitches in software and report them to developers before software is released to the public, Yang said.

A separate issue which could cause your computer to crash or worse, to completely die is the virus. Viruses are programs which seem harmless, but actually contain code to corrupt your computer . These bugs can spread from one computer to the next, just like the viruses that spread between people.

Got a question? Email it to Life's Little Mysteries and we'll try to answer it. Due to the volume of questions, we unfortunately can't reply individually, but we will publish answers to the most intriguing questions, so check back soon.