Im not sure where the installation files are stored, but this might help you.
Go here: http://linuxiso.org/distro.php?distro=44
and download Knoppix. Is a linux distro that runs from CD. If you have your bios set to boot from CD before HDD, at least you'll be able to access you HDD before the installation does, and delete it. Knoppix will create a shortcut to your hardd rive on the desktop. Hey, maybe you'll fall in love with it and install to the HDD and forget about microsoft and all their bs.