Seems easy right? Use the downloader, and in a few minutes it will be fixed. My fault for not realizing 100% is not actually 100%.
Just download the : Diablo-III-8730-enUS-Installer-downloader.exe
Everything will be OK!
But guess what? Blizzard has gracefully decided to remove the downloader from their site. Instead we have an installer. I downloaded it on March 15th, the downloader is long gone from my system because I had the complete game downloaded... nope.
So I just choose a location with the installer and it will recognize that I already have everything downloaded, RIGHT? Of course not, that would be easy. No matter what I do the installer ignores the existing files.
So I am now stuck downloading another 8gig, when I already downloaded it, because Blizzard didn't think ahead. I have limit internet usage, thanks Blizzard. Very appreciated.
Very disappointed that a problem that should be fixed in 2 minutes is causing me to re-download an entire game.