ener.hlp (Topic list)
Important Notice
The pages on this site contain documentation for very old MS-DOS software, purely for historical purposes. If you're looking for up-to-date documentation, particularly for programming, you should not rely on the information found here, as it will be woefully out of date.
Device I/O error (ERR: 57)
■ An input or output error occurred while your program was
  using a device such as the printer or a disk drive.
 
■ If you need additional help, move the cursor to a keyword
  and press F1 to open the Help window.