hi, i have just downloaded ubuntu 10.10 32bit, made a bootable cd and tried to boot from it but with no success.

when i restart my computer with cd in the tray i can't get to the installation screen, it simply won't boot from my cd(like my cd is not bootable). Same thing using bootable usb(followed the steps provided on ubuntu.com)

i have changed boot order(cdrom first,hdd second) but same thing.

any ideas? thanks