I am trying to upgrade a machine from RedHat 8.0 to 9.0, however I can't find a way to
make it boot from the CD-ROM. Fiddling with the BIOS doesn't seem to do it, under the
CD-ROM boot listing I get options of "none" and "disabled"; the machine just skips to
the hard drive boot. I'm a newbie, and I haven't found anything relating to this exact
problem in these forums or by using google; I'm asking for advice on the options I have
come up with on my own:

1. When I'm running RH8, I can insert the CD-ROM and it will autorun. A window pops
open asking my if I want to install RH9 packages. If I proceed, it comes up with a list
of packages to install, including some who's RH8 versions are already on the
machine. Since there is no plain "install" option I am concerned that if I just go ahead
and install the RH9 packages then my machine will become some kind of hybrid, no
longer functioning properly as either a RH8 or RH9 device. Normally I'd just try it out,
but even though the entire system was just backed up, I'd rather not have to try and
restore some VERY important thesis data that's there now. Is my concern warranted?

2. If I open the tower up, I should be able to connect the CD-ROM to the motherboard
in a new master or slave slot and have the BIOS detect it properly, right? If so, I
assume I can then boot from the CD-ROM....

Thanks in advance for any and all help!

If your CD Rom drive is connected to an IDE controller, powered on, AND jumpered correctly, you should see your BIOS detect it after POST.

If it shows up in the Primary Master/Primary Slave(or secondary) listing, then it should just be a matter of changing your boot order.
Ensure that your BIOS is set to autodetect devices on your IDE controller, so your CD Rom shows up upon computer start.
The BIOS doesnt need to detect drives for them to detect in an OS environment, yet if you want to boot from CD, it does.
Maybe this is the problem?

Thanks for the details, I'll look into that....