Just follow the simple steps Below:
1)Right click on the Google Talk shortcut.(note that this is not the one on the task bar it is the one on desktop or on START menu).
2)click on Properties.
4)On the Target textbox, add in the /nomutex to the end of the line so that it looks like below (or you can simply copy and paste the below syntax and replace the original).
“c:program filesgooglegoogle talkgoogletalk.exe” /nomutex
5)Click on OK.
you dont hav to do anything after this and CLICKING ON MANY TIMES ON GOGLE SHORTCUT GIVES YOU DIFFERENT GOOGLE TALK WINDOW………
ALSO U WILL HAV MANY SHORTCUTS IN TASKBAR