How can I Check my application Is running from CD

Or if You want to do it in an earlier application creation state.

program Project1;

uses
  Forms,Windows, Sysutils,
  Unit1 in 'Unit1.pas' {Form1};

{$R *.res}

begin
  Application.Initialize;
  if GetDriveType(PChar(ExtractFileDrive(Paramstr(0)))) <> DRIVE_CDROM then
    begin
    Application.MessageBox('You must run this program from CD','Error',MB_OK);
    end
  else
    Application.CreateForm(TForm1, Form1);
  Application.Run;
end.

Thanks a lot, But I think it can't recognize Virtual CD drive. Is there any way to prohibit using virtual-cd drive?