I had to format my c drive and reinstalled Window. Before doing so I saved the MP#tag map on an other drive, afraid to lose all (nearly 80) actions I made. Now I can't find a file where the actions are stored. Where does MP3tag stores user made actions and action groups?

it depends on what windows version you use. copy&paste this in the adress bar of the windows explorer: %appdata%\Mp3tag\data\actions