The 7th Guest 25th Anniversary Edition comes with a bunch of new features to an old game such as showing you where you can click and updated music. Although they've also replaced some favorite things of mine such as the title screen's perspective Ouiji board, and access to my saved games. I also enjoyed it for collection purposes of having every version I can get. So when I found out that the 25th Anniversary installs to the non-anniversary folder, I was kinda bummed out to say the least.

So here is how I recovered the old install.

1. Go into the properties of 25th and set it to only update when you start the game. Then go to the properties of the previous game version and do the same.
2. Find the local files folder through properties or via Steam\SteamApps\common\the7thguest
3. Rename the7thguest folder to the7thguest 25th.
4. Open Properties for the older version of The 7th Guest and pick the option to check integrity of game files. Steam will see they are missing and begin to reinstall the game. Mine also restored the saved games, which included the completed Open House save 0, so that was cool!

Whichever version you want to play, rename it to The7thguest in the Steamapps/Common folder before starting it up.