Instant messages are text messages that you can send to other people who are online when you are. Your message is delivered immediately, and the person you sent the message to can respond immediately-just as in a face-to-face conversation. You can do much more than just send text messages to other people. You can have audio and video conversations, place a phone call from your computer to almost anywhere in the world, hold an online meeting, play games, share programs that are installed on your computer, and more. The messenger is a special software program to send and receive instant messages over the Internet.

There are currently two dominating messengers on the Internet: MSN Messenger from Microsoft Corporation, and ICQ Messenger from ICQ Networks. The latter has a longer life and a wider spread in Europe. Other messengers include Yahoo! Messenger, AIM (AOL) Messenger, Trillian, and more. A basic messenger enables you to send instant messages to anyone on your contact list, see when your friends are online, share photos and files easily, use expressive emoticons to quickly communicate your mood, page a contact's mobile phone, make worldwide phone calls, receive alerts about local traffic, news, weather, sports, and travel, find out instantly that you have a new e-mail in your Inbox.

Often times you are interested in having a backup copy of your message database and your messenger's contact list, to be able to recover your contacts after a computer crash, a virus or system re-installation. Backing up your messenger data can be quite a challenging task. The recent releases of most messengers usually keep its data either under the folder they are installed in or under one of the user profile folder subfolders. Typically, you can start your search from:

C:\Program Files\

C:\Documents and Settings\User Name\

Older releases of AIM (AOL), Yahoo!, MSN, and ICQ messengers keep their settings at the following registry paths:

HKEY_CURRENT_USER\Software\Mirabilis\ICQ\DefaultPrefs\

HKEY_LOCAL_MACHINE\Software\Microsoft\MessengerService\

HKEY_CURRENT_USER\Software\America Online\AOL Instant Messenger (TM)

in various registry variables. For example, ICQ stores the path to the message store in Database variable. Additionally, UIN Dir variable keeps track of the directory with the ICQ contact list (ICQ contacts). You can back up messenger data either manually or automatically.