FreeDOS

[psxphill]

I've used the below guide before with flawless results:

http://www.howtogeek.com/136987/how-to-create-a-bootable-dos-usb-drive/

Yeah Rufus is excellent. I've had a problem copying some bootable isos to a usb stick as it's not a universal method.

IIRC it uses SYSLINUX like the official instructions.

http://www.freedos.org/wiki/index.php/USB

I don't know if it's possible for freedos to be the bootloader.

I've just found out that you can only put one partition on a USB pen drive. It is not the same as an external hard drive.

You can put more than one partition on the disk, Windows just doesn't like more than one partition on a disk that says it is removable.

http://www.prime-expert.com/articles/a05/enabling-multiple-partitions-on-removable-usb-storage-devices.php

"Usually external USB HDDs are fixed disks and USB thumbdrives are removable disks in Windows."

My latest external hard drive says it's removable and I couldn't find any way to change it, so the partitioning is also limited by Windows.
 
 I decided against multiple partitions in the end, but this will do it.
 
 http://forum.tabletpcreview.com/threads/win-8-1-format-a-sd-card-with-multiple-partitions-make-it-gpt-uefi-bootable-make-any-removable-storage-usb-appear-permanent.59815/

[psxphill]

But it also means that you don't have to bother with anything else than downloading the program in question to get it to work, provided you have the packet driver for your network card.

It depends on what software you want to use. If for example you want to use the dos lanman client then you need a driver for that and a packet driver shim so that applications can share it.

http://www.windowsnetworking.com/j_helmig/doscltcp.htm
 http://comp.protocols.tcp-ip.ibmpc.narkive.com/aRkDXHOI/lanman-and-packet-drivers

I used to use novell netware and packet driver shims and that was a similarly hairy experience.