When I'm working with cd live I see 3 cd-rom drives that I've got in my computer.....

When I'm working with installed knoppix on hd.I see only one cd-rom drive by me created..so, how can I create and access the other two?(DVD & CD-Writter).

Be patience with me I'm walking for firtsh time on linux.

Thanks in advance.

Regards.........almola.