* Go to Start menu --> Run --> Type regedit.
* Go to HKEY_CURRENT_USER -->> Software --> Yahoo --> pager -->Test.
* On the right pane, right-click and choose new DWORD value .
* Rename it as Plural.
* Double click and assign a decimal value of 1.
* Now close Registry Editor and restart Yahoo! Messenger.
* For signing in with new ID open another Messenger .
