This explains how use a DOS boot floppy to install from a USB-connected CD/DVD drive, when the PC BIOS does not support booting from USB devices.

This has been tested with Ubuntu 6.06 LTS Server, but may be adaptable to other versions.


  • A floppy drive
  • A USB-connected CD or DVD drive
  • Ubuntu installation CD (6.06 LTS Server is know to work)
  • MS-DOS or Windows 95/98 boot disk with MSCDEX.EXE
  • Cypress DUSE USB drivers
  • linld 0.97


  1. Copy DUSE.EXE and DUSELDR.COM from the DUSE package, and LINLD.EXE (sometimes LINLD097.EXE) to the boot floppy.
  2. Examine the isolinux.cfg file in the isolinux directory of the Ubuntu CD to determine the necessary parameters for linld.

For example:

LABEL install
  menu label ^Install to the hard disk
  kernel /install/vmlinuz
  append  preseed/file=/cdrom/preseed/ubuntu-server.seed initrd=/install/initrd.gz ramdisk_size=16384 root=/dev/ram rw quiet --
  1. Create a text file on your boot floppy, perhaps called options.txt, and paste in the all the parameters except the kernel and initrd.

For example:

preseed/file=/cdrom/preseed/ubuntu-server.seed ramdisk_size=16384 root=/dev/ram rw quiet --
  1. Make a note of the name and location of the kernel and initrd files if different from above.


On the target computer:

  1. Connect and power up the USB CD/DVD drive and insert the Ubuntu installation CD.
  2. Boot using the boot floppy.
  3. Load the DUSE driver

A:\> duseldr a:\duse.exe

The USB drive should be detected at this stage, otherwise refer to the DUSE documentation for further options.

  1. Load the CDROM extensions

A:\> MSCDEX /D:USBCDROM  /S  /M:15 /V 

Check that the CD is now readable using dir d:

  1. Bootstrap the Ubuntu installer from the installation CD using linld

A:\> linld097 image=d:\install\vmlinuz initrd=d:\install\initrd.gz cl=@options.txt

Ubuntu should boot from the CD and the installer should start automatically.


  • It should be possible to use FreeDOS instead of MS-DOS
  • It should be possible to use some versions of loadlin.exe instead of linld.exe

Installation/FromCDwithBootFloppy (last edited 2008-06-27 10:14:49 by localhost)