Trouble upgrading firmware of MOSER BAER DH-20A3S DVD Drive

Hi,

I wanted to know how to upgrade the firmware of my Moserbaer DH-20A3S DVD Drive. Current firmware is 9M73. I Need to upgrade it but cant do with firmware provided at website : 9P58_20A3S.

KINDLY TELL ME HOW TO UPGRADE MY FIRMWARE.

THE ERROR IS
No matched drive detected!
This utility is for ATAPI DVD A DH20A3S drive.

Detected drives :
3-1-0-0 G:MOSER BAER DH-20A3S 9M73

PLEASE TELL ME HOW TO UPGRADE FIRMWARE

THANK YOU.