What drive letter is your CD ? There is some code in qemu*/qemu-knoppix.bat which needs to find the CD drive letter. and only works if the drive letter is D,E,F,G,H,I,J, or K (I think. Can't check right now). If that's the problem, copy all the files from the CD to a directory; make the obvious change to the 'bat' file; and make a new CD. (Or issue a 'subst' command. Gave me quite a surprise when I did that by accident.) The new CD should 'boot' under Windows but not 'real'; to do the 'dual-capable' one you need the right 'mkisofs' command. Knoppix documentation will show it.

Another possibility is that you have an old version of Windows. I have seen success with XP, but failure with ME and 95. I have not tried others. I presume it's something about the compilers that were used to build 'qemu' producing code that will only work on newer versions of Windows. Mind you, "Got to upgrade to XP in order to run Linux" is not going to get much sympathy

Kanotix-for-Windows is constructed differently, and should 'boot' under Windows whatever drive letter you use. You can derive a Kanotix which boots 'real' by looking for the '.iso' file in the root directory of the CD. I like Kanotix.

If that doesn't fix it, copy the files from the ISO to disk and poke around with the QEMU documentation (in the qemu* directory, or qemu's web site) and adjust things until they run. If all else fails, there's always the source ... though I didn't need to recompile anything to make these isos. Just packaging. Honest. QEMU is good.

Cut and paste the commands and error messages here. Maybe I'll be able to help,or someone else will be able to help both of us.

If you can leave BitTorrent connected, it helps me. I have only 32 kbyte/second of uplink bandwidth, and rather a lot of ISOs to seed.