Before you install Microsoft Office 2010 Beta deinstall Office Live Addin 1.4! If you don't do it, you will not be able to deinstall it after you upgrade from Office 2007 to Office 2010 Beta. If you try to deinstall it after upgrading, the deinstall will fail with a message "You can't deinstall Live Addin because you have the wrong Office version." I hope Microsoft comes up with a solution or I have a messy task ahead, worst case a clean Win7 installation.