Computer Basics Lesson 2: Turning the Computer On and Off

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One thing a computer definitely needs to work is electricity! A desktop computer must always be connected to a power outlet, while a laptop may operate on its own internal battery for a few hours. In any case, without power the computer is pretty useless. In this lesson, we’ll cover the basics of how to turn on and off a computer.

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The Power Button: for turning on the CPU

A desktop computer has a power button on the front. By pushing in on the button and then releasing it, you turn the computer on. You should hear a noise like a fan or a vacuum cleaner, and some lights will appear on the front of the computer. Here is a picture of a typical power button:

Power button 

Note the green light that indicates that the power is on!

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Separate Power Button for the Monitor

You may also need to switch on the monitor in order to see what the computer is displaying.  A similar power button will usually be found in the lower right hand corner of the monitor screen.

Monitor and CPU power buttons 

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Power Strips

Often, a computer is plugged in to a power strip, or surge protector.  This helps protect the computer from power fluctuations or lightning storms, and it also allows a person to turn the computer and monitor on at the same time using the power strip on/off button.


power strip 

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Power Buttons on Laptops

Power buttons on laptops are usually found at the top of the keyboard. Laptops can be turned on when the laptop isn’t plugged in, but the battery has a limited life – usually a couple of hours.


You should rarely use the power button to turn a desktop or laptop computer OFF. There are a few housekeeping chores a computer needs to do before it turns off, and by using the power button you prevent the computer from turning off in a controlled manner. Instead, use the following method:

Turning Off a Computer

Use the mouse to click on the Start Button at the lower left hand side of the desktop. When the menu appears, click on Turn Off Computer. Finally, click on Turn Off. This is the sequence for a computer with the Windows XP operating system. It may be slightly different if you have a different version of Windows, but the idea is the same.

There are occasions when a computer is not able to turn off. If it gets stuck and will not finish turning off, you may need to use the power button. To do this, hold the power button in until you hear the computer stop and see the screen go blank. Doing this may result in an error message when you turn the computer back on, but will usually not harm the computer.

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Interesting Tidbit

The power button on a computer (and many other devices) displays shapes which come from a standard of the International Electrotechnical Commission (IEC):

Symbols for On and Off 

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Most desktop computers, when off, are actually in standby mode and use a small amount of power. If they are turned off with a power strip or are unplugged, they are completely off.


Find the power button on your computer. Turn it off and listen and watch for lights. The computer takes a few minutes to turn fully on. After the screen stops changing and the computer quiets down, use the Start button to turn the computer off again. How long does it take?

Vocabulary and Glossary

Power button
The button on a computer that is pushed in and released to turn the computer on. It should not normally be used to turn the computer off.
Power strip
A row of power outlets attached to a cable that allows multiple appliances to be plugged into one electrical outlet and turned off and on as a group. It often also acts as a surge protector, offering moderate protection against damage from power spikes and lightning storms.
In computing, to turn a feature (or computer) on and off again, by pressing one key or button to turn the feature on, then pressing the same key or button again to turn the feature off.
Standby mode
A mode in which electronic appliances are turned off but under power and ready to activate on command.

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More Information

How to turn on a computer:

Is it better to turn off a computer, or leave it on?

Turning on and off a Windows Vista computer:

To visit the previous websites, place your mouse over the underlined link above then click. You must be connected to the internet in order for the link to work.

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