for getting multiple gtalk
1.create a gtalk shortcut on the desktop
2.right click that icon and select properties and then
3.then in the target place u will see like this

""C:\Program Files\Google\Google Talk\googletalk.exe" /startmenu"

4.rename it as""C:\Program Files\Google\Google Talk\googletalk.exe" /nomutex"

5.click apply an the ok

6.u r done.now u r able to use multiple gtalk by clicking that shortcut