msiexec /x setup.msi /l*vx log.txt
http://blogs.technet.com/b/richard_macdonald/archive/2007/04/02/how-to-interpret-windows-installer-logs.aspx
msiexec /x setup.msi /l*vx log.txt
http://blogs.technet.com/b/richard_macdonald/archive/2007/04/02/how-to-interpret-windows-installer-logs.aspx