Description from softpedia :
A free and useful utility that allows you to run multiple instances of Yahoo! Messenger
Y! Multi Messenger allows you to run multiple instances of Yahoo! Messenger instead of only keeping one open.
This is perfect for those who run under several names. There are others out like this...but have an "update prompt", this does NOT have that!
Yahoo! Messenger for Vista:
We currently do not have a compatible version of YMulti Messenger for the newest Yahoo Messenger for Windows Vista!
Y!Multi v8 and v9 Instructions:
The version 8 patching program is NOT version specific, it will work with all versions of YM 8! All you need to do is launch the Y!Multi Messenger.exe file and then you can select to enable or disable the polygamy patch. Once its patched (either way) it will remain that way until changed again. The only time you will now use the Y!Multi Messenger.exe file is to change the actual patching, otherwise, you will now use the normal Yahoo Messenger icons.
Installation Instructions:
Before installing, please read ALL included documentation! Run the installation setup program to install Y!Multi Messenger. This will automatically install to C:Program FilesYahoo!Messenger. If you have installed Yahoo Messenger to a different folder, make sure to reflect the correct path in the Y!Multi Messenger setup wizard. Failure to have it install to the Yahoo Messenger program files folder will likely result in dll (driver file) errors.
Up/Downgrading Instructions:
Should you upgrade or downgrade versions of Yahoo Messenger, please delete the Y!Multi Messenger.exe file from the Yahoo program files folder first, then uninstall/upgrade Yahoo Messenger. Then if you are wanting to install Multi, make sure you have the same version of it and install it. It is important to delete the Y!Multi Messenger.exe file before up/down grading it as sometimes it may not get overwritten and can cause errors!