its very easy. do the steps: Start --> Control Panel --> Add/Remove Programs.
Everything that concerns MSN, like Windows Live Essentials, Messenger + Live etc.. just click on Change/Remove one by one on all those related to MSN.
You get 2 options Uninstall or Repair. Click on repair. The updates will b done. The only thing is that with the Messenger Live+ Repair you will lose all your configuration on your MSN. After that, reboot. Then all must work fine! Reconfig your MSN settings...
this is also a problem with automatic updates. if you are seeing this message, you will also have problems loading automatic updates. go to the microsoft website and check for updates. it will search for your machine and offer all available updates. install all updates offered
Don't know if this will help or apply. I found a forum with the logon issue(unable to log on or get messages). Uninstall Windows Live family safety component(add remove programs). Once this was removed all HTTP 400 and other errors stopped, logon successful. Note there are many Live components I removed Family Safety only.