The use of computers in movies...

Word processors never display a cursor.

You never have to use the space-bar when typing long sentences.

All monitors display inch-high letters.

The most relevant information is displayed in a separate windows right in the middle of the screen, but there's never an Ok button to other way to close it.

High-tech computers, such as those used by NASA, the CIA, or some such governmental institution, will have easy to understand graphical interfaces. Those that don't, have incredibly powerful text-based command shells that can correctly understand and execute commands typed in plain English.

Corollary: you can gain access to any information you want by simply typing "ACCESS ALL OF THE SECRET FILES" on any keyboard.

Likewise, you can infect a computer with a destructive virus by simply typing "UPLOAD VIRUS" (see Fortress).

All computers are connected. You can access the information on the villain's desktop computer, even if it's turned off.

Powerful computers beep whenever you press a key or whenever the screen changes. Some computers also slow down the output on the screen so that it doesn't go faster than you can read.

The really advanced ones also emulate the sound of a dot-matrix printer. (See The Hunt For Red October or Alien)

All computer panels have thousands of volts and flash pots just underneath the surface. Malfunctions are indicated by a bright flash, a puff of smoke, a shower of sparks, and an explosion that forces you backwards.

Corollary: sending data to a modem/tape drive/printer faster than expected causes it to explode.

People typing away on a computer will turn it off without saving the data. (See the opening credits for The Hunt For Red October)

A hacker can get into the most sensitive computer in the world before intermission and guess the secret password in two tries.

Any PERMISSION DENIED error has an OVERRIDE function (see Demolition Man and countless others).

Complex calculations and loading of huge amounts of data will be accomplished in under three seconds. Movie modems (especially the wireless ones they must be using when they're in the car) usually appear to transmit data at the speed of two gigabytes per second.

When the power plant/missile-site/whatever overheats, all the control panels will explode, as will the entire building.

If a disk has got encrypted files, you are automatically asked for a password when you try to access them.

No matter what kind of computer disk it is, it'll be readable by any system you put it into. All application software is usable by all computer platforms.

The more high-tech the equipment, the more buttons it has (Aliens). However, everyone must have been highly trained, because none of the buttons are labelled.

Most computers, no matter how small, are able to produce reality-defying three-dimensional, active animation, photo-realistic graphics, with little or no detailed input from the user.

Laptops, for some strange reason, always seem to have amazing real-time video phone capabilities and the performance of a CRAY Supercomputer.

Whenever a character looks at a VDU, the image is so bright that it projects itself onto his/her face (see Alien, 2001, Jurassic Park).

Either a Jacob's Ladder or a Van Der Graaf Generator is absolutely necessary for the operation of new, experimental computers (especially when built by brilliant scientists), although in real life, these devices do absolutely nothing.

One can issue any complex set of commands in a few keystokes (see Star Trek).

The internet connects to everything in the movies. You can edit credit records, search hotel registries, lookup police criminal files, search (and edit) drivers license databases, edit social security files and more just using the internet! (see The Net)

Smashing the VDU prevents the whole system from working (see Speed).

You can launch nuclear missles from any bedroom using an analog modem, but only if you know a single secret password (see War Games).