If your computer will boot from USB, this will probably be the easiest route for installation. Assuming you have prepared everything from Section 3.6.2, “Boot Device Selection” and Section 4.3, “Preparing Files for USB Memory Stick Booting”, just plug your USB stick into some free USB connector and reboot the computer. The system should boot up, and unless you have used the flexible way to build the stick and not enabled it, you should be presented with a graphical boot menu (on hardware that supports it). Here you can select various installer options, or just hit Enter.

If you have a set of optical discs, and your machine supports booting directly off those, great! Simply configure your system for booting off an optical disc as described in Section 3.6.2, “Boot Device Selection”, insert the disc, reboot, and proceed to the next chapter.

Note that certain optical drives may require special drivers, and thus be inaccessible in the early installation stages. If it turns out the standard way of booting off an optical disc doesn't work for your hardware, revisit this chapter and read about alternate kernels and installation methods which may work for you.

Even if you cannot boot from optical disc, you can probably install the Debian system components and any packages you want from such disc. Simply boot using a different medium and when it's time to install the operating system, base system, and any additional packages, point the installation system at the optical drive.

If you have problems booting, see Section 5.4, “Troubleshooting the Installation Process”.

To boot the installer from hard disk, you must first download and place the needed files as described in Section 4.4, “Preparing Files for Hard Disk Booting”.

For GRUB2, you will need to configure two essential things in /boot/grub/grub.cfg:

An entry for the installer would be for example:

menuentry 'New Install' {
insmod part_msdos
insmod ext2
set root='(hd0,msdos1)'
linux /boot/newinstall/vmlinuz
initrd /boot/newinstall/initrd.gz
}

Booting from the network requires that you have a network connection and a TFTP network boot server (and probably also a DHCP, RARP, or BOOTP server for automatic network configuration).

The server-side setup to support network booting is described in Section 4.5, “Preparing Files for TFTP Net Booting”.

There are various ways to do a TFTP boot on i386.

When the installer boots, you should be presented with a friendly graphical screen showing the Debian logo and a menu:

Debian GNU/Linux installer boot menu

Graphical install
Install
Advanced options                            >
Accessible dark contrast installer menu     >
Help
Install with speech synthesis

	Note
	This graphical screen will look very slightly different depending on how your computer has booted (BIOS or UEFI), but the same options will be shown.

Depending on the installation method you are using, the “Graphical install” option may not be available. Bi-arch images additionally have a 64 bit variant for each install option, right below it, thus almost doubling the number of options.

For a normal installation, select either the “Graphical install” or the “Install” entry — using either the arrow keys on your keyboard or by typing the first (highlighted) letter — and press Enter to boot the installer. The “Graphical install” entry is already selected by default.

The “Advanced options” entry gives access to a second menu that allows to boot the installer in expert mode, in rescue mode and for automated installs.

If you wish or need to add any boot parameters for either the installer or the kernel, press Tab (BIOS boot), or e then down arrow three times then end, to edit the “linux” line of the boot entry (UEFI boot). This will bring the boot command for the selected menu entry and allow you to edit it to suit your needs. Note that the keyboard layout at this point is still QWERTY. The help screens (see below) list some common possible options. Press Enter (BIOS boot) or F10 (UEFI boot) to boot the installer with your options; pressing Esc will return you to the boot menu and undo any changes you made.

Choosing the “Help” entry will result in the first help screen being displayed which gives an overview of all available help screens. To return to the boot menu after the help screens have been displayed, type “menu” at the boot prompt and press Enter. All help screens have a boot prompt at which the boot command can be typed:

Press F1 for the help index, or ENTER to boot:

At this boot prompt you can either just press Enter to boot the installer with default options or enter a specific boot command and, optionally, boot parameters. A number of boot parameters which might be useful can be found on the various help screens. If you do add any parameters to the boot command line, be sure to first type the boot method (the default is install) and a space before the first parameter (e.g., install fb=false).

	Note
	The keyboard is assumed to have a default American English layout at this point. This means that if your keyboard has a different (language-specific) layout, the characters that appear on the screen may be different from what you'd expect when you type parameters. Wikipedia has a schema of the US keyboard layout which can be used as a reference to find the correct keys to use.

Note

If you are using a system that has the BIOS configured to use serial console, you may not be able to see the initial graphical splash screen upon booting the installer; you may even not see the boot menu. The same can happen if you are installing the system via a remote management device that provides a text interface to the VGA console. Examples of these devices include the text console of Compaq's “integrated Lights Out” (iLO) and HP's “Integrated Remote Assistant” (IRA). To bypass the graphical boot screen you can either blindly press Esc to get a text boot prompt, or (equally blindly) press “H” followed by Enter to select the “Help” option described above. After that your keystrokes should be echoed at the prompt. To prevent the installer from using the framebuffer for the rest of the installation, you will also want to add vga=normal fb=false to the boot prompt, as described in the help text.

The graphical version of the installer is only available for a limited number of architectures, including 64-bit PC. The functionality of the graphical installer is essentially the same as that of the text-based installer as it basically uses the same programs, but with a different frontend.

Although the functionality is identical, the graphical installer still has a few significant advantages. The main advantage is that it supports more languages, namely those that use a character set that cannot be displayed with the text-based “newt” frontend. It also has a few usability advantages such as the option to use a mouse, and in some cases several questions can be displayed on a single screen.

The graphical installer is available with all CD/DVD images and with the hd-media installation method. To boot the graphical installer simply select the relevant option from the boot menu. Expert and rescue mode for the graphical installer can be selected from the “Advanced options” menu. The previously used boot methods installgui, expertgui and rescuegui can still be used from the boot prompt which is shown after selecting the “Help” option in the boot menu.

Just as with the text-based installer it is possible to add boot parameters when starting the graphical installer.

Note

The graphical installer requires significantly more memory to run than the text-based installer: 810MB. If insufficient memory is available, it will automatically fall back to the text-based “newt” frontend. If the amount of memory in your system is below 780MB, the graphical installer may fail to boot at all while booting the text-based installer would still work. Using the text-based installer is recommended for systems with little available memory.