This guide is now obsolete and has been superseded by Download Windows 10 Version 1903 and Create a Bootable USB in Windows or Linux which instructs with the newer Build of Windows 10 and also addresses a common error found with Unetbootin.
You need a Windows 10 Installation .iso for more details see Download Windows 10 RS2 Version 1703 Build 15063 Creator's Update Using Direct Download Links.
Making a Bootable USB with UNetBootin
Before making the Bootable USB you should use Disk to format the USB as FAT32 (otherwise it may not boot particularly in a UEFI BIOS). This can be done in Ubuntu and other Linux distributions by using Disk. Press the Ubuntu orb:
Then type disk:
Select your USB flash drive to the left and then under your USB select the settings crank:
Select format partition:
You can format to overwrite data or you can format to assign all data to free space. Select Don't overwrite existing data (quick) to prolong your USB storage device unless it is seriously infected:
Ensure you select FAT so it can boot in a UEFI BIOS:
Name the USB and select Format:
Select Format again:
Ensure it shows up as FAT (32 Bit version). Then exit Disks:
You can use the UNetbootin program to make a Bootable USB.
It can be run on Linux, Apple OS and Windows. For Windows I prefer to use Rufus.
Select Download (Linux).
You will be presented with the installation instructions. The install and use of this utility unfortunately requires use of the Terminal which may scare some people but it is quite easy.
Select the Ubuntu orb and type terminal.
Select the terminal
Type in the following
sudo add-apt-repository ppa:gezakovacs/ppa
To proceed you will be asked for your password. Type in your password into the command prompt and press [Enter]
After you have done so you will get some information about Unetbootin. Press
It will begin to install:
Now type in:
sudo apt-get update
Now type in:
sudo apt-get install unetbootin
You will be asked whether you want to continue.
Final the install will be done:
If you then go to the Ubuntu orb:
Type in Unetbootin and select to launch the program:
Unfortunately you will get this error message. Lets open the terminal again:
UNetbootin will now launch:
Select Disk Image and make sure the .iso is selected. Load it:
Select the TH2 .iso:
Select the USB drive – its labelling isn't too userfriendly so its recommended to only have one USB flash drive inserted in your system:
Select Ok the program will now extract and copy the files from the .iso to the USB:
When finished select [Exit]
This USB will boot in both a legacy BIOS and a UEFI BIOS. You can use the setup.exe on the Bootable USB to perform an inplace upgrade from an older build of Windows 10 or use it to perform a clean install. For more details see Clean Installing Windows 10 RS2/Version 1703/Creator's Update with UEFI and Secure Boot.