How to Use A Computer Safely Without Leaving a Trace

Computer User

This document explains in layman's terms how one may use a computer while keeping the computer safe from viruses and without leaving behind any history or personal information.

Last updated: March 20, 2010

Summary

Computers normally store traces of information about their usage. It is possible to protect yourself from the computer (and vice versa) using a live cd. Live CDs may be purchased for a few dollars or created using a blank CD-R, free software and a suitable computer.

Contents

Introduction

Many people who don't own a computer still want to be able to use one from time to time, usually to do things like web surfing, email and word processing. The problem is that anything you do on someone else's computer may have effects beyond your immediate usage. Any software or viruses installed (intentionally or otherwise) will live on the computer permanently and any personal information or web browsing history may persist.

The reason for this is that a computer has two types of storage:

temporary storage (called 'RAM'):
wiped clean every time the computer is restarted.
permanent storage (a 'hard drive' or 'hard disk'):
retains information when the power is off.

The key to protecting your information from the computer and vice versa is to bypass permanent storage and do everything in temporary storage. This way when the computer is turned off no traces of your activity remain.

The easiest way to do this is called a live CD.

What is a Live CD?

Live CD

A live CD contains a small but complete computer system on a CD. When a computer is powered on with a live CD in it, it will bypass its normal system and use the one on the live CD. The live CD system lives only in temporary storage. One can safely use the web, word processor, printer, etc. from the live CD without touching the computer's 'regular' system. Once you're done, just eject the live CD and turn the machine off. No trace of information from the live CD session will persist.

There are many types of live CDs, which is confusing for computer amateurs (and professionals alike!). If you're the inquisitive type I suggest you read up as much as possible. For people who want things as simple as possible I will cut to the chase.

The easiest way to get a live CD is to buy one. I happen to like a live CD called Knoppix which has been around for years and has always 'just worked' for me (I'm not affiliated with them). You can buy a knoppix live cd for a few dollars. The Knoppix software itself is free, the money is for the physical CD, the postage and the time.

Of course, that assumes that you have some money, a shipping address and some time to wait for it to arrive. If you're feeling thrifty or ambitious, however, you can create your own live CD for the cost of a blank CD and some time.

Live CD Recipe

Caveat

One important caveat to creating your own live cd is that in order to do so you must do some of the things that you are inherently trying to avoid in the first place — permanently affecting the computer you're using. In order to create a live cd you must download and install an application and download the CD file itself. Luckily both these operations are reversible once you are done.

Ingredients

  1. Blank CD-R

    One or more blank, writable CDs (a CD-R).

    These are pretty common these days, any office supply stores or pharmacy should have them, maybe even grocery stores. They shouldn't cost more than about $1/each.

    NOTE: 'CD-R' means the disc can be recorded exactly once; screw up and it goes in the trash. 'CD-RW' means the disc can be written to more than once, meaning that if you screw up you can try again.

  2. Access to a computer with the following things:
    • CD-R Logo

      A CD-recordable drive.

      Usually the drives will indicate this on the front. Anything that mentions the terms 'CD-R', 'CD-RW', 'DVD-R', 'DVD-RW' or 'SuperDrive' will suffice. The newer the computer the more likely it will have one of these drives, they have been relatively common since the late 1990s.

    • A hard disk with about 700MB of free space

      Any machine made after the year 2000 or so should have plenty of space.

    • Relatively fast internet access.

      Dial-up modems can work but will take hours and may fail. Caveat emptor.

Steps

  1. Download and install a CD-recording application.

    A private or internet café computer may already have CD-recording software installed. If not I suggest ISO recorder which is small, free and easy to use. The key feature of a CD-recording application is that it must support ISO files or CD images. Dragging and dropping your files to the CD WILL NOT WORK. You must install a separate, ISO-capable CD-recording application.

  2. Save Link

    Save the (large) Knoppix CD file to your computer.

    If you can't figure out how to use the link above click here.

    This can take anywhere from a few minutes to many, many hours depending on the speed of your internet connection.

  3. Find the file you just downloaded. It will start with "ADRIANE-KNOPPIX".

    Usually the file will be downloaded to the Desktop, which means if you minimize all the open windows you should be able to see an icon for it. Depending on your computer's setup you may have to look around for it, try places like My Downloads or other nonsense.

  4. Insert the blank CD into the computer's CD writing drive.

    To open the drive push the button on the front.

  5. Burn (write) the Knoppix file to the CD.

    For ISO recorder follow these instructions. For other CD recording software look for something mentioning the phrase 'Write' or 'Burn' and 'ISO' or 'CD Image'.

  6. If all went well you now have a live CD.

Using a live CD

  1. Insert CD

    Insert the live CD into the computer's CD drive.

    (If you just created it then it's already in there.)

    If the computer's power is off then you either need to turn the power on to make the button work or manually eject the drive with a straightened paperclip.

  2. Restart

    Restart the machine or turn it on.

  3. Knoppix Boot Screen

    You should see a different startup than usual.

    You will see a penguin at the top of the screen and a bunch of colored text. This is a good thing. Let it start up.

    If you see the usual Windows start then it didnt work. Bummer. There are three likely possibilities:

    1. The KNOPPIX file didn't download, or only downloaded partially. The file should be about 680MB in size. Pay attention to any error messages. If the links on this page are broken (it's possible), then google "download knoppix" and find a .iso file.
    2. You used CD software other than ISO recorder and you copied the files normally instead of making an ISO copy. This will not work. Go back to Step 1, install ISO recorder and try again.
    3. You used ISO recorder and the disc is OK, but the computer isn't reading the CD before it starts Windows. By default the computer should check the CD first, but it's possible to change this order. You need to change the order in which the computer reads its boot media. This may be outside the novice's realm of expertise, but try printing out and following the instructions.
  4. Knoppix Desktop

    Once startup is complete you should see something that is similiar to, but different than, Windows.

    This is your live CD desktop.

    Everything you do is temporary; anything you create, install or change will be ERASED when the computer is restarted (not a good environment for drafting up your resumé).

    Your web browser is the Earth icon on the bottom left. Have fun!

  5. Optional: Clean up after yourself.

    Restart the computer without live cd.

    Delete the KNOPPIX file you downloaded and uninstall the ISO recorder software.

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