|Restore Original Values on Uninstall|
What I'd like to know is how do you know that the values you backed up are still valid (if restored) when you'd like to uninstall? Or are you only going to do this if the user immediately (defined less than an hour of so) since installation?
The environment at install and uninstall differ unless no installation of software has taken place between your installation and uninstallation steps... Replacement of "original" data may corrupt another products installation (and its probably made a backup of YOUR register as well).
Its hard to say what the best action should be with Windows Issues like this but perhaps restoration of a "safe" value may be better?