Multiple Yahoo Messanger IN the same PC (machine)

the steps for this trick are
Go to run.Type 'regedit'.
Go to HKEY_CURRENT_USER.
Double click 'softwares'.
Click on 'Yahoo'.
Then click on 'Pager'
Click on test. On the right panel,right click and create a DWORD value.
Name it as 'plural'. By double clicking,change the default value to 1.