Mandrake 7.2

Greets;

I seem to have a problem. I had a working CDR of Mandrake 7.2, so I made a
cd image of it, and have it on my hard drive. Well, I lost that working
cd, so I burned another cd with the cd image that I have of it, all the
files are on it and whatever, but it won't boot from startup. When it
checks for cdrom, it says failed, like its not a bootable cd. But, if i put
it in, when Windows is running, it popups with some annoying screen about
linux mandrake.

Is there any reason why it wouldnt make it a boot cd, from a boot image? Am
I doing something wrong?

-Tyler