it will support more variety of the dvd+r outside there. So I am thinking to update it.
Yes correct. And you dont need real time DOS mode.
Just check with your manufacturer site. They must have the firmware for your drive and the application that is used to flash the firmware. You can get both of them from that site for your model. Its just load and click operation , its easy.
EDIT: This might be of help . http://www.americal.com/pg/dvd-burner-compat.html