Hi all!

First of all, I am brand-new to Linux, so please be patient with my stupid questions.

Some time ago I installed Knoppix (in Debian mode) on my old DELL Inspirion 7000 laptop. Now I'm trying to replace the old install with a newer version of Knoppix in Knoppix mode. I have created a disk image that I'd like to use automatically at boot time. However, it seems that I cannot boot into the newer HD image without the Knoppix CD in the CD-ROM drive! With the CD in the drive I am prompted to choose to boot up using the HD image or the one on the CD. Without the CD, however, the laptop boots directly into the old Knoppix/Debian install.

What am I doing wrong? How do I replace the original install with the new one?

Please spell out what to do step by step because I am still figuring out my way around Linux and am still weak in terminology. Thanks to everybody in advance!