You can login into Yahoo Messenger multiple times with
different user names without using any third party application. You
just need to modify the registry key for this.
Follow these steps:
- Click Start and then click Run and type Regedit and Hit enter.
- Navigate to the following Registry Key
- HKEY_CURRENT_USER\Software\Yahoo\pager\Test
- Highlight the Test Key,
- On the right side do a right click a choose New > DWORD Value
- Name it as Plural
- Double click and assign the Value 1
- Close registry and restart Yahoo Messenger and try Multiple Login.