Install Silverlight on Windows 7 (64bit) with IE 9 (all updates installed).
Run Silverlight.exe, install gets to 89% displays text "Installation failed".
On second installation attempt running Silverlight.exe I get a dialog "The feature you are trying to use is on a network resource that is unavailable. The "Use source" displays a path that is no longer valid "d:\93ef3ffb0bf5358228b0b2d7\" (presumably from the first failed install). Browsing brings up the correct new path "D:\d2c7c1760d6ac6f96afeaa\silverlight.msi" - selecting OK returns "installation failed" again.
Silverlight shows up in the installed programs list under "Programs and Features", however attempting to uninstall results in the same dialog described above.
Searching my drives for Silverlight.* results in a SilverlightMSI.log and a Silverlight0.log which I will attach.