I have an older laptop doesn't allow boot to USB. It has a CD drive instead of DVD player. How do I create a bootable CD that can then load USB so I can install Windows from my thumb drive?
plop should let you do it - its a bootloader that runs off various external devices and should let you bootstrap a USB key or such.
However, older versions of windows probably will not boot off a USB key gracefully (there's tools like win2flash, but i've not had luck with them), and i doubt windows 7 or vista (which do support a USB install well) will run very well on a system that is old enough not to support USB boot.