Hello,
We were working with a customer today who was unable to get our package to run (it would have been an upgrade). They were able to get through the initial installer dialogs, but basically right after they clicked the "Install" button, they got a pop-up saying "Are you sure you want to cancel". Clicking "No" starts the installer over. Clicking "Yes" exits the installer without modifying the system.
We were able to generate a verbose MSI log (which you can find here: http://x509crypto.org/downloads/install3.log). We made sure that Windows Installer is allowed to run on the system and that there were no pending reboots. Nothing helpful appeared in the Windows event viewer, unfortunately.
Any guidance would be greatly appreciated.