ener.hlp (Topic list)
MS-DOS Shell (Alt+F,H)
■ Temporarily leaves the programming environment so you can
  use MS-DOS commands. Visual Basic remains in memory.
 
■ To return to the programming environment, type EXIT at the
  MS-DOS prompt and press Enter.
 
■ Tip: While at the command prompt, be careful not to delete
       any files that the programming environment might need
       (for example, loaded files, include files, and
       libraries).