You can adjust your chat history settings in Gmail at any time. Chat history for Google Talk is only available to users who are signed in with a Gmail username.
From Gmail:
- Sign in to Gmail.
- Click Settings at the top of any Gmail page, and open the Chat tab.
- From the Chat tab:
- Select 'Don't save chat history in my Gmail account' to disable chat history saving, or,
- Select 'Save chat history in my Gmail account' to enable chat history saving.
- Click Save Changes.
Keep in mind that if you've disabled chat history saving, people you chat with may still choose to save chat histories in their Gmail settings. If you would prefer that someone you're talking to doesn't save your chat, you can take the conversation off the record. If you're talking to someone who is connected to the network with a desktop chat client, it's possible that his or her software is keeping a separate copy of the chat history.