"We all do dumb things now and then, and computer users are no exception. Inadvertently pressing the wrong key combination or innocently clicking OK in the wrong dialog box can change important settings that alter a computer’s behavior or even crash the system.
Nervous newbies are often fearful that one wrong move might break the computer forever. Luckily, short of taking a sledge hammer to the box, the consequences aren’t usually quite that dire. Even so, users often do create problems for their computers and for your network. Here’s a description of common missteps you can share with your users to help them steer clear of preventable problems." – Content courtesy of 10 dumb things users do that can mess up their computers