FromWindows
InstallUbuntuWithoutRemoveableMedia
This page is an adaptation of Marc Herbert's http://marc.herbert.free.fr/linux/win2linstall.html
This page will guide you through obtaining the files necessary to boot the Ubuntu installation from a FAT or NTFS partition, thus allowing you to install Ubuntu without any sort of removeable media. This guide assumes that you are running Windows NT, 2000, XP, or any other NT-based Windows. You can also perform a similar procedure on Windows 9x, but I'm not sure exactly how. Marc Herbert's site also desribes a method using LOADLIN, but suspect it's possible using GRUB as well.
* Create a directory called boot in the root directory of the first primary partition of your hard drive (usually drive c:\, which it will be referred to as from now on).
* Download linux and initrd.gz from http://archive.ubuntu.com/ubuntu/dists/hoary/main/installer-i386/current/images/netboot/ubuntu-installer/i386/ and save them to boot.
* Download Grub For Dos from http://grub.linuxeden.com/wakka.php?wakka=UploadFile/files.xml&action=download&file=grub_for_dos-0.4.0.tar.gz
* Extract grldr from the archive to c:\grldr. The rest of the files in the archive are unnecessary.
* Append c:\grldr="Install Ubuntu" to c:\boot.ini.
* Create a new folder in c:\boot\ called grub, and in grub create a new text file called menu.lst.
* Open menu.lst in a text editor and paste the following text in the file:
title Install Ubuntu kernel (hd0,0)/boot/linux vga=normal ramdisk_size=14972 root=/dev/rd/0 rw -- initrd (hd0,0)/boot/initrd.gz
* Save menu.lst, reboot, and select "Install Ubuntu" twice. You now have a network installation of Ubuntu going.
This procedure should be possible using a disk image, but it may be necessary to use a different kernel and pass some special argument in menu.lst to tell it to boot from the CD image (I've done it using Knoppix).