In china and some other countries the users are impossible to install Yahoo messenger from its installer. After many failures it may display a link of the full package download link. But why not Yahoo displays it on the download page? It is really ridiculous and it makes very easy to understand why Yahoo should go down. Yahoo simply does care about the users.
Yahoo Messenger 9.0
http://download.yimg.com/ycs/msg/dl/msgr9/us/ymsgr900_2162_us.exe
Yahoo Messenger 10.0
http://rd.software.yahoo.com/msgr/10/standalone/msgr10us.exe
