If you want to save an existing file in a different file format, choose one of the following:
If the file is already referenced from other files, you may want to change the format without changing the name or its location. As you cannot have two files with the same name saved in the same directory, even in different formats, the only option is to overwrite the file.
If you want to have versions of a file in various formats within the same directory, you must save each file with a different name.
If you would like to keep the name of the file but change the format, you must save the file in a different directory.
If you modify an ANSI text file and the modifications include characters outside of the ANSI characters set, when you try to save your changes, the Save As dialog box will open and you need to either overwrite the ANSI file with a file of the same name but in a different format, or rename the file and save in Unicode or UTF-8 format .