Often it is required to create a bootable USB stick for installation of an operating system or for running a program. "Bootable at boot" means that when you turn on the computer, instead of loading the operating system (which may be Windows, Linux or Mac OSX) from the hard disk, another program is loaded which is located on a CD / DVD, on the USB stick or on the memory card.
For CDs and DVDs, you just need to burn the ISO to the disc instead to make a USB pen bootable the process is a bit different and changes depending on the file and the operating system used.
You cannot simply copy files from an ISO or IMG disk image directly to the USB drive without making it bootable on boot.
There are various ways of making the USB stick or memory card bootable when the computer is booted, which change depending on the file, system or program that is to be started.
READ FIRST: How to change the boot order of the computer
1) Copy a program (as ISO file) to a bootable USB stick using Windows
To make any USB stick bootable where you want to copy the contents of an ISO file, you can use one of the programs to burn ISO to USB, such as Rufus or Etcher.
Just select the ISO file to copy, the USB stick to use and then press the button to create the bootable USB drive.
2) From a Linux ISO image
On the programs to use and download the guide is in another article where it is explained how to create a USB stick bootable at boot from ISO Linux .
In summary, the best Windows program to use is UNetbootin on which you just have to select the ISO file of the Linux distribution you want to install or that you want to start live (without installation) and copy the files as if you were burning a CD.
Another alternative program, recommended by Ubuntu, is Universal USB Installer (always indicated in the specific guide).
Similar tools can also be used on Linux.
For example, Ubuntu includes a tool called Disk Creator for creating bootable USB drives.
UNetbootin also works on Linux.
3) From an IMG file
Some programs like antivirus and even some operating systems instead of the ISO file provide the IMG file.
An IMG file is a raw image of a disk that must be written directly onto a USB drive.
In this case the program to always use to write an IMG file on a USB stick or memory card is Win32 Disk Imager
Simply select the downloaded IMG file and the tool will write it directly to the unit, deleting any other files inside.
With this tool you can also create IMG files from USB drives and SD cards.
On Linux you can use the dd command to write an IMG file on a removable device.
Precisely, on Ubuntu, you can use the command:
sudo dd if = / home / user / file.img of = / dev / sdX bs = 1M
replacing /home/user/file.img with the path where the IMG file is located and / dev / sdX with the path of the USB stick.
4) Create the USB stick of the Windows 7 ISO
As seen, you can still download the Windows 7 installation ISO
Instead of burning this ISO to a disc, you can copy it to a USB stick making it bootable on boot.
Microsoft provides the Windows 7 USB / DVD tool to do this job quickly and easily.
Alternatively, in another article it is written how to create a bootable USB stick on boot to install Windows
5) USB stick from the Windows 10 ISO
If you have a valid license, you can download the Windows 10 ISO installation disc directly from the Microsoft website and then create a USB drive without using other programs.
It is Microsoft that provides the download and creation tool of the bootable USB stick.
But if you already have an ISO of Windows 10, without downloading it again, you can create the USB stick with Rufus or Etcher.
6) USB stick for Windows 7 Via DOS
If necessary, you can create the Windows 7 or 8 installation USB stick via DOS using manual commands in a DOS prompt.
7) USB stick to install Mac OS X
You can create a boot disk with Mac OS X s by downloading the latest version of OSX from the Mac App Store and using an automatic tool.
The guide is always in this blog to install OSX Mavericks from scratch on the Mac from a USB stick .
8) To install Windows on Mac from USB stick
To install Windows on a Mac via Boot Camp, just use the Mac's Boot Camp tool which provides a wizard from scratch for installing Windows 7 on a Mac.
9) Create Mac OS X installation USB stick from Windows
10) Install Windows 10 and 8.1 on USB drive to use it in portable version
11) Copy your PC to a bootable and portable USB, Windows 10, 7 or 8 drive
