Run multiple Yahoo Messengers

You can log into multiple yahoo accounts on yahoo messenger using this simple Registry edit. Open the Registry editor (Start->Run, type regedit and hit Enter).

Before we proceed any further, its always better to backup the registry before you make any changes to it.
To backup, goto File -> export -> give a file name and make sure the "Export range" is set to "All" and click save.

Now, navigate to the following path:

HKEY_CURRENT_USER\Software\Yahoo\Pager\Test

On the right pane,right click and select New-> DWORD Value. Name it as "Plural" (without the quotes). Now double click on the newly created DWORD to open up the 'Edit DWORD Value' window. Give it a hexadecimal value of 1 and press OK.

That's it. You're done. Exit the Registry Editor. You can now log into Yahoo! Messenger with multiple accounts simultaneously :)

And should you get the need to disable this, simply double click on the registry backup which you saved earlier.