{
This tip works with Windows 2000 (NTFS 5) and later
These 2 functions are defined in windows.pas, but they're defined wrong. In this
case our own definition.
}
function EncryptFile(lpFilename: PChar): BOOL; stdcall;
 external advapi32 name 'EncryptFileA';
function DecryptFile(lpFilename: PChar; dwReserved: DWORD): BOOL; stdcall;
 external advapi32 name 'DecryptFileA';
{....}
procedure TForm1.Button1Click(Sender: TObject);
begin
 if not EncryptFile('c:\temp') then
  ShowMessage('Cannot encrypt directory.');
end;
procedure TForm1.Button2Click(Sender: TObject);
begin
 if not DecryptFile('c:\temp', 0) then
  ShowMessage('Cannot decrypt directory.');
end;