What do you mean you kept a backup, a copy of the folder? The correct way to make a backup of your sounds is to make a soundpack: Plus > Soundlibrary > import/export button choose export. To restore/import take the same route but choose import.
Also you may not have used the newest Messenger Plus! Sound Library Fixer..the old one did not support Windows Live Messenger,
get the newest. If that one doesn't work either then please give us some more info like which version of Messenger, which Plus! version and which OS and if you are on a limited or admin account.
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