I had the same prob. Since there's very little on the internet, I've pasted the gist of the live chat that helped me resolve the issue below.
Me: Hello. Thanks for helping me today. I have Espanol LA 1,2, and 3
on Windows 7. I am getting error code 4112 after I try to load my
already activated and updated product. I tried uninstalling and
reinstalling and I am still getting 4112.
Tech: Click on Start->Click on Computer->Click on C: Do you see
program data folder?
Tech: Then click on the organize on the top. Then click on folder and
search options. Then click on the view tab.
Me: ah. show hidden files folders and drives
Tech: Yes. Have a check on it, click ok. Now you can see program data.
Me: now i'm able to get into program data, rosetta stone, then Totale
Me: now i see the file dynamic stored paths
Tech: Delete dynamic stored paths in Rosetta stone and TOTALe folder
Tech: Close all the windows and open the program
Tech: Do not click on any user name. Insert the language level cd in
Tech: Please click on the icon next to the question mark with small
Tech: you can close the windows which shows the files of the cd.
Tech: Click on add/remove languages
Tech: Click on add a language level
Tech: right. done. Now it says: A newer version of this language level
already exists on your computer. Are you sure you want to overwrite?
Me: Perhaps it's just referring to updates that were made when I had
installed it before?
Tech: Yes. Over write
Tech: Install all three levels with your three discs and their updates