"I have written this complete article on my blog also:
I am describing here a method to install Linux without using a DVD
ROM or CD Drive; I have checked it myself. There are many ways to
do so you can install Linux by 1) booting from the network; 2)
having an ISO image on your hard disk; 3) booting from USB; 4)
installing a linux system from scratch by building your own.
"I am assuming that Linux is not installed on your system and
neither grub or lilo is there. This method is using an OpenSuse
10.2 Image but is same for Fedora or Debian or any other distro.
There is one check point in case you used Nero to copy CD or DVD
image then it might have been possible that you copied the image
and it is file with dot nrg extension in that case you need to get
the ISO from NRG.
"I have installed by all the above methods but I am describing
here the simplest one since there are many new comers who would not
be able to understand other methods. Before doing all this make