Last week I ran into an issue where I needed to boot into DOS in order to update some firmware on our servers. Problem was, the servers didn't have a floppy drive, but they did have USB and CD-Rom. I had a bootable CD-Rom in the form of the Ultimate Boot CD (UBCD), which has a batch file included for turning a USB memory stick into a bootable device, complete with the contents for the UBCD.
A USB memory stick is allot easier to carrier around then a CD. In fact, I keep a 2GB USB memory stick on my key chain, and the UBCD only takes up ~120MB. The only downside is the UBCD contents are stored on the root of the USB drive. I keep things clean by creating a folder named _files in the root, which is where I stick all of my files, and this seems to work. I also wanted to add DSL, as it can be booted, or run from inside windows.
Installation - UBCD
Obtain a USB drive/stick. I picked up a 2GB San Disk Cruzer for $17 on sale at best buy. It comes with something called U3, which thankfully you can uninstall by using a program you can download from here. You have to go thru a bunch of marketing screens telling you how cool U3 is.
Next Download the ultimate boot cd and burn it to a CD. You could probably also mount it using a mounting tool but I did not try this. Use the ubcd2usb.bat file located in tools\ubcd2usb to format your usb drive, make it bootable and install the contents of the UBCD to it.
I've run into a couple of problems on this step. First, it seems to fail under Vista, but I only had one USB stick left to format at the time. It works fine on WinXP and Win2k3.
For the SanDisk U3 stick, I formatted it first from the command prompt after removing the U3 software and this seems to have helped it. I think it may have gotten corrupted when I tried using Vista after removing the U3. A co-worker of mine has the exact same USB stick, but I know he used XP and had no problems
Install DSL
The following instructions are based on this forum post which was written for DSL 3.2. My instructions work with the latest version (4.x) and allow you to boot from your USB drive using Qemu, or boot into DSL when your computer boots up.
First download the latest version of DSL. I used this link (Check the DSL download page for a list of current mirrors), which is for the embedded version (zip file, not an .iso). Then I extracted the contents of the .zip file to a temporary folder (c:\temp\dsl) and created a folder on the root of my USB drive called DSL (\DSL).
Copy KNOPPIX to the root of your USB drive, then copy the all of the extracted DSL contents except KNOPPIX to /custom/DSL. Edit the .bat files in /custom/dsl updating the path to KNOPPIX as /KNOPPIX. Finally edit \custom\custom.cfg with a text editor adding a label for choosing DSL. Your custom.cfg might look something like this:
MENU INCLUDE /menus/defaults.cfg
LABEL back
MENU LABEL ..
KERNEL menu.c32
APPEND /menus/main.cfg
LABEL dsl
MENU LABEL DSL V4.2
KERNEL /custom/dsl/linux24
APPEND ramdisk_size=100000 init=/etc/init lang=us apm=power-off vga=791 initrd=/custom/dsl/minirt24.gz nomce noapic quiet BOOT_IMAGE=knoppix
You should now be able to boot DSL from the Qemu emlator by using the bat files in /custom/dsl, or boot DSL from the UBCD menu (Custom Tools\DSL 4.2). I could not figure out how to get DSL to boot thru UBCD with KNOPPIX in the DSL folder, only with it in the root of the USB drive. A minor inconvenience.
Final Thoughts
I decided to remove the autorun.inf and website folder which was installed from UBCD. I was going to remove the tools folder, but then realized that by keeping those on there, I could easily create this same setup on other USB sticks for friends.
A similar utility disk is the Ultimate Boot CD for Windows (UBCD4Win). The application you download from the UBCD4Win takes files from a WinXP (SP2 recommended) disk, and creates a bootable CD with utility applications. However, it sounds like you are limited to booting computers which have a similar version of Windows (XP, Server 2003), especially for the NTFS utilities.