type
  {Для индикации процесса копирования}
  TCallBack = procedure (Position, Size: Longint);

procedure FastFileCopy(const InfileName, OutFileName: string;
          CallBack: TCallBack);
const
  BufSize = 3*4*4096; { 48Kbytes дает прекрасный результат }
type
  PBuffer = ^TBuffer;
  TBuffer = array [1..BufSize] of Byte;
var
  Size : integer;
  Buffer : PBuffer;
  infile, outfile : file;
  SizeDone, SizeFile: Longint;
begin
  if (InFileName <> OutFileName) then
  begin
    buffer := nil;
    AssignFile(infile, InFileName);
    System.Reset(infile, 1);
    try
      SizeFile := FileSize(infile);
      AssignFile(outfile, OutFileName);
      System.Rewrite(outfile, 1);
      try
        SizeDone := 0; New(Buffer);
        repeat
          BlockRead(infile, Buffer^, BufSize, Size);
          Inc(SizeDone, Size);
          CallBack(SizeDone, SizeFile);
          BlockWrite(outfile,Buffer^, Size)
        until
          Size < BufSize;
        FileSetDate(TFileRec(outfile).Handle,
        FileGetDate(TFileRec(infile).Handle));
      finally
        if Buffer <> nil then
          Dispose(Buffer);
        System.close(outfile)
      end;
    finally
      System.close(infile);
    end;
  end
  else
    raise EInOutError.Create('File cannot be copied into itself');
end;

procedure FileCopy(const SourceFileName, TargetFileName: string);
var
  S, T : TFileStream;
begin
  S := TFileStream.Create(sourcefilename, fmOpenRead );
  try
    T := TFileStream.Create(targetfilename, fmOpenWrite or fmCreate);
    try
      T.CopyFrom(S, S.Size ) ;
      FileSetDate(T.Handle, FileGetDate(S.Handle));
    finally
      T.Free;
    end;
  finally
    S.Free;
  end;
end;

uses
  LZExpand;

procedure CopyFile(FromFileName, ToFileName : string);
var
  FromFile, ToFile: file;
begin
  AssignFile(FromFile, FromFileName);
  AssignFile(ToFile, ToFileName);
  Reset(FromFile);
  try
    Rewrite(ToFile);
    try
      if LZCopy(TFileRec(FromFile).Handle, TFileRec(ToFile).Handle)<0 then
        raise Exception.Create('Error using LZCopy')
    finally
      CloseFile(ToFile);
    end;
  finally
    CloseFile(FromFile);
  end;
end;

uses
  // !!! важно
  ShellApi;

function WindowsCopyFile(FromFile, ToDir : string) : boolean;
var
  F: TShFileOpStruct;
begin
  F.Wnd := 0; F.wFunc := FO_COPY;
  FromFile:=FromFile+#0; F.pFrom:=pchar(FromFile);
  ToDir:=ToDir+#0; F.pTo:=pchar(ToDir);
  F.fFlags := FOF_ALLOWUNDO or FOF_NOCONFIRMATION;
  result:=ShFileOperation(F) = 0;
end;

// пример копирования
procedure TForm1.Button1Click(Sender: TObject);
begin
  if not WindowsCopyFile('C:\UTIL\ARJ.EXE', GetCurrentDir) then
    ShowMessage('Copy Failed');
end;