In Nero did you choose the option to make a bootable CD? I'm not using Windoze at the moment, but you should be careful when you choose the options. I believe it should just say to burn an image, and not make a bootable CD. Nero uses Caldera DOS to make a CD bootable to a Windoze OS. Just burn Slack as an image and it will be bootable. If you can't figure it out from this post, and no one else posts, then post back and I'll boot into Doze and get the exact option for you.