You might want to try it out with a boot floppy. I remember that SuSe 7.0 came with an installation boot floppy, if it doesn't start...
If your hardware isn't supported, there isn't much you can do as far as I know.
I know that tere is a website that can tell you wether your hardware works with Linux, but you shouldn't have problem with regular IDE CD-Roms. Unfortunatelly, I forgot the address of it.... may be a google search will help.
SuSe has a good hardware database at http://hardwaredb.suse.de/index.php?LANG=en_UK
. May be you want to check there. If it works with SuSe, you have good chances that it works with Mandrake too. I somehow can't figure your system specs at Dell, so I can't help you further.
To make sure that your CD's work fine, test them with another machine.
That's all I can think of for now.... hope it helps