I was recently trying to reinstall the .Net 4 beta at home and came across this particular error:

Windows6.1-KB958488-v6001-x64.msu returned non-MSI error code: 0x80092004 - Cannot find object or property

When rebooting didn’t fix the problem I figured it was unlikely to be caused by files being held open or not updated during uninstallation. Since I didn’t want to wipe the machine just for this I decided to poke at the problem a bit further. I found that this error is known to occur if you try to uninstall and reinstall too quickly. After uninstalling there is a background update done to a catalog of components. If something delays that update and you try to reinstall right away, you can end up with this error due to incorrectly cached component information.

After uninstalling, rebooting and then waiting for an hour solved the problem.