7. I have stored a worksheet but I do not know where it is located. What can I do?
Files are stored in the directory that has been defined using: Tools > Options
However, in case the default directory is changed at the moment of saving a file, all files used in the actual working session (while you do not exit Minitab) will be stored in the new directory. To find out where files are being stored you can proceed to save the actual worksheet and observe what directory is being used.
Another possible situation is that perhaps you saved the file as a Project (MPJ extension) – which happens when clicking on the Save icon – and you are trying to open it as a worksheet (MTW extension) or vice versa. Make a search with *.* so all files contained in the directory are displayed.