...install a screensaver?

uses
  shellapi;

procedure InstallScreenSaver(const FileName: string);
begin
  { Set this screensaver as default screensaver and open the properties dialog}
  ShellExecute(Application.Handle, 'open', PChar('rundll32.exe'),
    PChar('desk.cpl,InstallScreenSaver ' + FileName), nil, SW_SHOWNORMAL);
end;


procedure TForm1.Button1Click(Sender: TObject);
begin
  InstallScreenSaver('c:\YourScreenSaverFile.scr');
end;