I do not know how to im - Google Computers & Internet

Download Google Talk from http://www.google.com/talk/ and run the set up file.
After downloading google talk, once you sign in to google talk, you can start sending and receiving IMs from google talk contacts.
To send an IM on Google Talk, first, select a contact and click on their Google Talk username. An IM window will appear addressed to your Google talk contact. You can type your message in the google talk IM window and press Enter on the keyboard to send your mesage.