If you can't remove the saved games using the Ctrl + R key combination, launch the game, press Ctrl + L to open all saved files, select the one you want to remove using the mouse cursor and press the Delete key. If it doesn't help, go to Local Disk (C:) > Program Files > The Learning Company > Zoombinis > Maths Journey and open the folder entitled Zoombini. Here you will find all saved games. You can delete them using the Delete key.
