There are two different netinst CD images which can be used to install squeeze with the debian-installer. These images are intended to boot from CD and install additional packages over a network, hence the name 'netinst'. The difference between the two images is that on the full netinst image the base packages are included, whereas you have to download these from the web if you are using the business card image. If you'd rather, you can get a full size CD image which will not need the network to install. You only need the first CD of the set.

Download whichever type you prefer and burn it to a CD. To boot the CD, you may need to change your BIOS configuration, as explained in Section 3.6.1, “Invoking the BIOS Set-Up Menu”.

It's also possible to install from removable USB storage devices. For example a USB keychain can make a handy Debian install medium that you can take with you anywhere.

The easiest way to prepare your USB memory stick is to download hd-media/boot.img.gz, and use gunzip to extract the 256 MB image from that file. Write this image directly to your memory stick, which must be at least 256 mb in size. Of course this will destroy anything already on the memory stick. Then mount the memory stick, which will now have a FAT filesystem on it. Next, download a Debian netinst CD image, and copy that file to the memory stick; any filename is ok as long as it ends in .iso.

There are other, more flexible ways to set up a memory stick to use the debian-installer, and it's possible to get it to work with smaller memory sticks. For details, see Section 4.3, “Preparing Files for USB Memory Stick Booting”.

Some BIOSes can boot USB storage directly, and some cannot. You may need to configure your BIOS to boot from a “removable drive” or even a “USB-ZIP” to get it to boot from the USB device. For helpful hints and details, see Section 5.1.4, “Booting from USB Memory Stick”.

It's also possible to boot debian-installer completely from the net. The various methods to netboot depend on your architecture and netboot setup. The files in netboot/ can be used to netboot debian-installer.

The easiest thing to set up is probably PXE netbooting. Untar the file netboot/pxeboot.tar.gz into /var/lib/tftpboot or wherever is appropriate for your tftp server. Set up your DHCP server to pass filename /pxelinux.0 to clients, and with luck everything will just work. For detailed instructions, see Section 4.5, “Preparing Files for TFTP Net Booting”.

It's possible to boot the installer using no removable media, but just an existing hard disk, which can have a different OS on it. Download hd-media/initrd.gz, hd-media/vmlinuz, and a Debian CD image to the top-level directory of the hard disk. Make sure that the CD image has a filename ending in .iso. Now it's just a matter of booting linux with the initrd. Section 5.1.3, “Booting from Linux Using LILO or GRUB” explains one way to do it.