Disable Ctrl+Alt+Del under Windows XP

procedure DisableTaskMgr(bTF: Boolean);
var
  reg: TRegistry;
begin
  reg := TRegistry.Create;
  reg.RootKey := HKEY_CURRENT_USER;

  reg.OpenKey('Software', True);
  reg.OpenKey('Microsoft', True);
  reg.OpenKey('Windows', True);
  reg.OpenKey('CurrentVersion', True);
  reg.OpenKey('Policies', True);
  reg.OpenKey('System', True);

  if bTF = True then
  begin
    reg.WriteString('DisableTaskMgr', '1');
  end
  else if bTF = False then
  begin
    reg.DeleteValue('DisableTaskMgr');
  end;
  reg.CloseKey;
end;

// Example Call:
procedure TForm1.Button1Click(Sender: TObject);
begin
  DisableTaskMgr(True);
end;