Bootable Pen Drive
There are many instances where a "DOS" or Windows 98SE bootable pen drive is required - for example, some BIOS updates or other low level updates can only be done in this way. (Stone is working to provide Windows update utilties wherever possible, but these arent always available yet).
If you need to create a DOS or Windows 98SE (or FreeDOS) bootable equivalent, please see some links to third party sites below which host various solutions.
Rufus - http://rufus.akeo.ie/
HP USB Format Tool - Download here
Windows 98 Boot files - here