1.Create a shortcut to GTalk on your desktop (if you dont have currently).
2.Go to the properties of the shortcut. There in the target, you’ll see something like: “C:\Program Files\Google\Google Talk\googletalk.exe”
3.Add /nomutex to that target line. Then the line would be this:
“C:\Program Files\Google\Google Talk\googletalk.exe” /nomutex4.“Apply” it and then click “Ok”.
5.Check out if it works, Enjoy Multi-GTalks and don't forget to comment to say it works:)