Translations by Mykola Tkach

This will delete all your saved passwords for wireless networks, instant messaging accounts, etc. Only do this if you can't remember the password you used for your keyring.

Press <keyseq><key>Ctrl</key><key>h</key></keyseq> (or click <guiseq><gui>View</gui><gui>Show Hidden Files</gui></guiseq>.)

Double click on the folder called keyrings.

Delete any files you find in the keyrings folder.

After you restart and log in you will be asked to enter your wireless networks password.

Use longer, more complicated passwords.

Choose a secure password

Make your passwords easy enough for you to remember, but very difficult for others (including computer programs) to guess.

Choosing a good password will help to keep your computer safe. If your password is easy to guess, someone may figure it out and gain access to your personal information.

People could even use computers to systematically try to guess your password, so even one that would be difficult for a human to guess might be extremely easy for a computer program to crack. Here are some tips for choosing a good password:

Use a mixture of upper-case and lower-case letters, numbers, symbols and spaces in the password. This makes it more difficult to guess; there are more symbols to choose from, so more possible passwords that someone would have to check when trying to guess yours.

A good method for choosing a password is to take the first letter of each word in a phrase that you can remember. The phrase could be the name of a movie, a book, a song or an album. For example, "Flatland: A Romance of Many Dimensions" would become F:ARoMD or faromd or f: aromd.

Make your password as long as possible. The more characters it contains, the longer it should take for a person or computer to guess it.

Do not use any personal information such as a date, license plate number, or any family member's name.

Do not use any nouns.

Choose a password that can be typed quickly, to decrease the chances of someone being able to make out what you have typed if they happen to be watching you.

Never write your passwords down anywhere. They can be easily found!

Use different passwords for different things.

Use different passwords for different accounts.

If you use the same password for all of your accounts, anyone who guesses it will be able to access all of your accounts immediately.

It can be difficult to remember lots of passwords, however. Though not as secure as using a different passwords for everything, it may be easier to use the same one for things that don't matter (like websites), and different ones for important things (like your online banking account and your email).

Change your passwords regularly.

You might not have the right codecs installed, or the DVD might be the wrong region.

Why won't DVDs play?

If you insert a DVD into your computer and it doesn't play, you may not have the right DVD <em>codecs</em> installed, or the DVD might be from a different <em>region</em>.

Installing the right codecs for DVD playback

In order to play DVDs, you need to have the right <em>codecs</em> installed. A codec is a piece of software that allows applications to read a video or audio format. If you try to play a DVD and don't have the right codecs installed, the Movie Player should tell you about this and offer to install them for you.

DVDs are also <em>copy-protected</em> using a system called CSS. This prevents you from copying DVDs, but it also prevents you from playing them unless you have <link xref="video-dvd-restricted">extra software</link> to handle the copy protection.

Checking the DVD region

DVDs have a <em>region code</em>, which tells you in which region of the world they are allowed to be played. If the region of your computer's DVD player doesn't match the region of the DVD you are trying to play, you won't be able to play the DVD. For example, if you have a Region 1 DVD player, you will only be allowed to play DVDs from North America.

It is often possible to change the region used by your DVD player, but it can only be done a few times before it locks into one region permanently. To change the DVD region of your computer's DVD player, use <link href="apt:regionset">regionset</link>.

Most commercial DVDs are encrypted and will not play without decryption software.

How do I enable restricted codecs to play DVDs?

DVD support cannot be provided by default in Ubuntu due to legal and technical restrictions. Most commercial DVDs are encrypted and so require the use of decryption software in order to play them.

Use Fluendo to legally play DVDs

You can buy a commercial DVD decoder that can handle copy protection from <link href="apt:fluendo-dvd">Fluendo</link>. It works with Linux and should be legal to use in all countries.

Use alternative decryption software

In some countries, the use of the below unlicensed decryption software is not permitted by law. Verify that you are within your rights to use it.

Install <link href="apt:libdvdnav4">libdvdnav4</link>, <link href="apt:libdvdread4">libdvdread4</link>, <link href="apt:gstreamer0.10-plugins-bad">gstreamer0.10-plugins-bad</link>, and <link href="apt:gstreamer0.10-plugins-ugly">gstreamer0.10-plugins-ugly</link>.

If you would like to play encrypted DVDs (see the legal note above), open the Dash and launch a <app>Terminal</app>.

Type the following into the screen which appears, then press <key>Enter</key>:

Enter your password to complete the installation.

Check that they have the right video codecs installed.

Other people can't play the videos I made

If you made a video on your Linux computer and sent it to someone using Windows or Mac OS, you may find that they have problems playing the video.

Ask the person having problems with playback if they have the right codec installed. They may find it helpful to search the web for the name of the codec plus the name of their video playback application. For example, if your video uses the <em>Theora</em> format and you have a friend using Windows Media Player to try and watch it, search for "theora windows media player". You will often be able to download the right codec for free if it's not installed.

If you can't find the right codec, try the <link href="http://www.videolan.org/vlc/">VLC media player</link>. It works on Windows and Mac OS as well as Linux, and supports a lot of different video formats. Otherwise, try converting your video into a different format. Most video editors are able to do this, and specific video converter applications are available. Check the <app>Ubuntu Software Center</app> to see what's available.

There are a few other problems which might prevent someone from playing your video. The video could have been damaged when you sent it to them (sometimes big files aren't copied across perfectly), they could have problems with their video playback application, or the video may not have been created properly (there could have been some errors when you saved the video).