It is fairly simple to install Kali Linux onto a portable device. In some situations, clients do not permit the use of an external laptop inside a secure facility. In those cases, typically a testing laptop is provided by the client to the pentester to perform the scan. Running Kali Linux from a portable device has more advantages during a pentest or RTE:

• It's in the pocket, in case of a USB or mobile device
• It can be run live without making any changes to the host operating system
• You can customize the build of Kali Linux and you can even make the storage persistent

There are a simple three steps to make a USB into a portable Kali from a Windows PC:

1. Download the official Kali Linux image from: http://docs.kali.org/introduction/download-official-kali-linux-images.
2. Download Win32 Disk Imager from: https://sourceforge.net/projects/win32diskimager/. We will be using Win32 Disk Imager 1.0.
3. Open the Win32 Disk Imager as administrator. Plug the USB drive into the PC's available USB port. Browse to the location where you've downloaded your image. You should be able to see what's shown in the following screenshot. Select the right drive name and then click Write:

Once complete, exit the Win32 Disk Imager and safely remove the USB. The Kali Linux is now ready as a portable device to be plugged into any laptop to boot it up live. It is also possible to generate a hash value using the Win32 Disk Imager. If your host operating system is Linux this can be achieved by two standard commands:

sudo fdisk -l

This will display all of the disks mounted on the drive:

dd if=kali linux.iso of=/dev/nameofthedrive bs=512k

That's it. The dd command-line utility does the convert and copy, if is used for input file , of is for output file, and bs is for the block size.