Many instant messenger programs offer the option to save your chat logs in an archive file. Whether you need to locate important information or simply want to relive a great conversation, you can use these archives to easily find the messages you need.
Open the Message Archive to view your previous Yahoo! Instant Messenger conversations. Click "Contacts" and select "Message Archive" to open the list of saved messages. By default, Yahoo! Instant Messenger is set to automatically save your messages in the archive.
View previous messages in Windows Live Messenger (previously called MSN Messenger) by opening the Message History. Click "File" and select "View Message History" to read past conversations. Message logging must be enabled; if it isn't, you can turn it on by opening the "Options" menu and checking the box in the "Messages" tab that tells the program to save a history of your conversations.
Retrieve Google Talk chat history from the "Chats" folder in your Gmail account. Enable this feature in the Settings menu of either the Google Talk client or your Gmail account.