I believe that method prevents you from saving the file over itself from excel, but you could change any of the cells and 'save as' another filename. Then overwrite the original from windows and hey presto... file changed.
the more secure way is to lock the cells with a password. By going to tools / protection / protect workbook and entering a password users are unable to change any cells in the sheet.
This method also allows you to unlock some cells but keep others locked, thus allowing users to enter values into tables etc if required.
Regards