Nero has always been a bit of a dog when I comes to installing and especially updating it.
Updates involve replacing the existing install with the updated one. I have had failures of one sort or another
while updating Nero over the years. They have gotten better with each version but it still a chore to perform updates.
It doesn't surprise me it's taking awhile to install Nero 9.
Having said that, I very much like Nero, it works great for "burning" .iso's, I've been using a paid version since v 6.
I'm even using a licensed version in Linux (NeroLinux 3).