That is as Booting from a CD, DVD or USB explained

That is as Booting from a CD, DVD or USB

What is boot?

The word boot is the verb of the word to boot (start), which refers to computer boot sequence or boot that has a computer at the time you switch it on.

All computers have a specific order of boot. Every time you turn on your computer, thebootloader , which is responsible for organizing the program boot sequence, you must verify that each component can be included in the boot in a sequential order. This order can be changed using the steps discussed below. A boot example:

1. Turn on the computer.
2. Try to boot from the CD-DVD, if there is nothing (no disk or a disk is not an operating system) goes to the next component.
3. Floppy Drive (floppy), if nothing happens to the next component.
4. USB (flash drive), if nothing happens to the next component.
5. Hard Drive (HDD), operating system found

If no operating system or program to perform some task (such as Memtest to check the integrity of the RAM) you will see a message stating: insert a boot disk or  insert boot disk .

Requirements to install an operating system

But what does the boot with the installation of an operating system? The boot is very important in the process of installing or repairing an operating system.

First, in order to install Windows or Linux you must first have a disk or flash drive engraved with the OS you want to use. Imagining that you have this you must configure the boot of your PC.

The first boot is usually configured to read the hard drive first and then the other units. This setting is recommended, since you avoid losing some time while checking all components before going to the hard drive where OS. This way you can save a couple of seconds when the team clothing. Anything goes when optimizing.

Now go into the game boot configuration. We must change the boot order to depart from the CD-DVD (if you have a disk) or USB (if you want to install from a USB flash drive.) This way you can run programs and OS installation components and decoration storage devices  and then save the files on your hard disk. If you boot from the hard part and you have an operating system that will happen:

1. Hard Drive (HDD), operating system found -> Home Windows and not looking for anything more.
2. CD-DVD, never happened around here.
3. Floppy Drive (floppy), never happened around here.
4. USB (pendrive), never happened around here.

That's why we must change the order before performing an installation. 
You can also boot from a floppy or network, but currently these methods are not widely used.

Modify the boot order

To change the order that boots your computer you must enter the BIOS. To enter the BIOS you have to press a key or several joints before displaying the logo of Windows or another operating system. You can mark (s) several times without stopping until a screen other than the usual.

If you do not know where you belong, check out this list of keys to enter the BIOS by brand:

Acer: Aspire, Power, Veriton, Extensa, Ferrari, TravelMate, Altos

Press Del or F2 immediately after lighting. For most Acer computers can also use F1 or Ctrl + Alt + Esc

Compaq Presario, Prolinea, Deskpro, SystemPro.

Press F10 while the cursor in the upper right corner of the screen is flashing. For most Compaq computers can use: F1, F2, F10.

Dell XPS, Dimension, Inspiron, Latitude, OptiPlex, Precision, Vostro

Press F2 when the Dell logo appears. For most desktops and notebooks from Dell you can use Ctrl + Alt + Enter or Delete, Fn + Esc or Fn + F1.

eMachines: eMonster, eTower, eOne, S-Series, T-Series

Click Tabular or Del while the logo is displayed on the screen. Other eMachine computers may use F2 to enter the BIOS.

Fujitsu: Lifebook, ESPRIMO, Amilo, Tablet, DESKPOWER

Press F2 when the Fujitsu logo appears.

Gateway: DX, FX, One, GM, GT, GX, Profile, Astro

Press F1 or F2 key several times after restarting the computer.

Hewlett-Packard (HP) TouchSmart, Vectra, OmniBook, Tablet

Press the F1, F2 or Esc after reboot. HP Tablet PCs may use F10 or F12.

IBM PC, XT, AT

Press F1 immediately after turning on the computer. For most of the IBM PC (including laptops) can use the F2 key.

Lenovo (IBM Antigua): ThinkPad, IdeaPad, 3000 Series, ThinkCentre, ThinkStation

Press F1 or F2 after turning on the PC. You can also use Ctrl + Alt + F3, Ctrl + Alt + Ins, or Fn + F1.

NEC PowerMate, Versa, W-Series

Press F2.

Packard Bell: 8900 Series, 9000 Series, Pulsar, Platinum, EasyNote, iMedia, iextreme

Press F1, F2 or Del to enter BIOS.

Sharp: Notebook Laptops, Actius Ultralite

Brand F2 after the computer starts.

Sony: VAIO PCG-Series, VGN-Series

Press F1, F2 or F3 after turning on the computer.

Toshiba: Portege, Satellite, Tecra

Press F1 or Esc after powering on the computer.

If the Windows logo appears and you spent! Restart the computer and try again.

If you enter the BIOS you will see an image like this:

From now on you have to be very careful and read the various options available to your team . There is no universal manual to modify the boot, as each option can be in different places.Background colors can also change, even sounds.

In this case we have a Phoenix BIOS. Each brand of BIOS and different versions have menu options and distinct distributions. I recommend you check option by option, without changing anything yet , which change the boot sequence.

For example we boot menu by Advanced BIOS Features -> First Boot Device . If you do not know how to move within the BIOS, on the underside or on the right side is a list of keys you can use to navigate and make changes. serves no mouse, only the keyboard .

Select the drive that you use CD-DVD or USB. Press F10 to save the changes. It will ask if you're sure to save your changes, you can mark Y (yes, yes) or Enter. This will also depend on the brand and version of the BIOS.

The computer restarts and now you can follow the instructions appearing on the screen to install the operating system. For Windows: Press any key to boot from CD or DVD ...

In new equipment, you can modify the boot much faster team. Generally the side of the message with the key to enter the BIOS, there is another who can say something like:  KEY to Enter Boot Menu . I leave you three examples of different keys to enter the Boot menu directly:

Modified with the arrow keys and press booting Enter when ready. If you start from a pendrive select Removable Devices or equivalent.

The beauty of this method is that the change is not permanent. It works only once and then a reboot is the configuration that has the previously saved BIOS.