>>A machine has Windows Live Messenger 8.5. When signing in it indicates a new version is available which you can choose not to install but then you cannot sign in with old version. So you accept installation and what happens: installation is aborted without explanation after 75+% progress.
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>>What can be the problem? I logged as user with administrator rights.
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>I ran into the same situation. I uninstalled all Windows Live components and downloaded a fresh installer from their website and ran that. Then, the installation worked fine and everything is now working as expected.
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>Jon

I finally was able to uninstall the Windows Live compoments but had to use Revo Unistaller which first tried the application uninstaller (failing as I had) and then went though the registry and disk to sort of force delete the application. I was then able to install latetst version of Live Messenger.

Thanks your help which focused me in uninstalling at any cost.

Alex