Alright, I think I know what you mean now. If you enter BIOS upon startup (I have a Dell, so my BIOS is likely to be slightly different than yours) you should see several fields to choose from that you can hit enter on go to a new screen where you can adjust various settings.
If you have a field that says ADVANCED, enter there. If not, search thru them all untill you find one that displays something to the effect of IDE CONFIG. Enter this field too. Now you should have 4 choices, Primary Master, Primary Slave, Secondary Master, and Secondary Slave. You choose which one is your CDRW/DVD drive and hit enter. There should be a box that says TYPE and to the right of it it should say NONE. Scroll over to NONE, hit enter, and find AUTO. Click enter on AUTO, and save changes and restart!
It sounds really confusing, I know, but try it and tell me how it goes!