1. Logout and Exit from Yahoo Messenger
2. Go to Start ----> Run.
3. Type regedit, then enter.
4. Locate to HKEY_CURRENT_USER\Software\yahoo\pager\Test
5. On the right pane , right-click and choose new Dword value .
6. Rename it as Plural.
7. Double click and assign a decimal value of 1.
8. Close registry and restart yahoo messenger