BIOS gives "boot error" on USB boot, CD boot works perfectly

[steev-p]

I have the same issue with my older Dell desktop.

The solution is to give the USB key zipdrive-like geometry (64 heads, 32 sectors per track)
You can do that from the Knoppix CD using the "mkdiskimage" script:
Note: This will erase all data on the USB drive

mkdiskimage -z /dev/sdx 0

-z means "use zipdisk geometry"
Replace /dev/sdx with your USB drive (use 'fdisk -l' or gparted to find out what your USB drive is called)
The 0 means automatically determine the size of the device.

Also might be required (but wasn't for me) is the -4 option, which means "use partition entry 4 (standard for zipdisks)". This option will cause the Knoppix installer to fail because it tries to install to partition #1 of the USB drive.

More info in the syslinux docs:
<edit>Sorry, not allowed to post links yet. Read /usr/share/doc/syslinux/usbkey.txt from the Knoppix CD</edit>

[utu]

@ secdroid.

I have formatted a 4 Gb usb as a single partition
of Fat32 with GParted, using a Knoppix 6.7 CD.
Then, also using the LiveCD, made a LiveUSB, allowing
2 GB for persistent store, and allowing grub to be
installed to the MBR of the USB.

This leaves about 1Gb unassigned on the USB for whatever
use I might make of it.
It leaves my computer's MBR unchanged;
I select USB from among the media boot choices already
available on my computer's boot program, whatever it is.

Works for me, and I don't know a simpler way.

If you are trying to install to a 1 Gb partition,
I don't think you will have enough room for any significant
persistent store. 2 Gb will work well enough, except don't
try a full upgrade of all programs.