function GetDiskVolSerialID( cDriveName : char ) : DWord;
var dwTemp1, dwTemp2 : DWord;
begin
GetVolumeInformation( PChar( cDriveName + ':\' ), Nil, 0, @Result, dwTemp2, dwTemp2, Nil, 0 );
end;
MessageDlg( 'Serial number: ' + Format( '%X', [ GetDiskVolSerialID( 'E' ) ] ),
mtInformation, [mbOk], 0 );