Kim Barloso

How to write an image to Windows flash drive in UltraISO


In this walkthrough of the Windows 7 and 8 operating system recovery series, I am going to show you how to create a full-blown Windows 7 bootable flash drive using UltraISO in 5 minutes. Typically, such a flash drive is used to restore the operating system in case of unforeseen circumstances - in particular, when the system cannot boot on its own. The point is that standard Windows 7 tools are often powerless when fatal errors occur. So the only thing left to do is to use a bootable flash drive to restore Windows. As mentioned at the beginning, for this purpose we will use a well-known application to work with iso-images and disk recording - UltraISO .

In addition, today many of us do not own a floppy disk drive and the Windows developers distributed their early products mostly on DVD- and CD-ROMs (although this is not true for Windows 10). Why not write a system image for further recovery to a usb flash drive to get rid of inconvenience forever? Besides, the benefits of a bootable flash drive are numerous:

  • you can always take it with you, having a fairly versatile Windows recovery kit at hand
  • making a bootable flash drive for Windows 7 using Ultra ISO, is quite simple - please read the manual below
  • the floppy drive may be overwritten at any time with custom /files
  • the device is detected and bootable on most system configurations and Windows operating systems
  • the bootable USB stick is faster and not prone to read errors

It is clear, that a Windows 7 distribution with a recovery kit should be on hand at all times - at the most critical moment it may turn out to be the only salvation after a Windows operating system crash. So without further ado let us get down to business - that is, creating a flash drive with Windows 7 "on board".

Step 1: Installing UltraISO, the software to write a bootable flash

To quickly create a bootable flash drive for Windows 7, we will need the well-known and latest version of UltraISO. You can download it from the official site or search the torrents for a free Russian version, preferably the latest, of Ultra ISO. The latest version currently available for download is 9.6, released in August 2014 (now this application for burning disks and flash drives is not updated very often). Conveniently, the program for creating a bootable distribution on a flash drive is quality localized and available on file hosting and file sharing sites for free. However, I advise you to honestly pay for using UltraISO in pro-version if it helps you to make a Windows 7 recovery flash drive.

Download the Russian version UltraISO from the official site of the program

Step 2: Downloading the Windows 7 distro from the Microsoft website

You may download the necessary Windows 7 distribution from the official Microsoft website or, again, from torrents - free, but not entirely fair. Perhaps you have a licensed or evaluation version of Windows 7 to create a USB flash drive-reanimator, you can create an image of the system, using a program to create a bootable flash drive UltraISO. But it would be better to use a writable ISO image, which you can also download from Microsoft web site - UltraISO will "digest" it much easier to create USB flash drive needed to boot and reactivate Windows OS later.

Loading OS distribution Windows 7 (8) to create a bootable USB Flash drive from torrent

In principle, any iso image of Russian or English Windows 7 or 8 will do for our purposes. The size of the distribution to be loaded onto a bootable flash drive may vary from 2 to 7 GB, so make sure you have enough space on your flash drive to create a bootable Windows 7 image.

In my situation as you can see I am using an iso image of W8.1x64_Enterprise_Reactor CD, correspondingly it is a 64-bit version of Windows 8.1 currently installed on the computer where I am writing this tutorial. In principle, the following methods are also valid for Windows 10: UltraISO is quite omnivorous.

Step 3. Recording and creating the bootable flash

Launch the Ultra ISO. Select File-Open..., and specify an ISO image to create a bootable Windows 7 flash disk. On the right side of the UltraISO window you will see the content of the Windows installation package you want to write to the flash drive.

The contents of the future Windows 7 recovery USB flash drive is displayed in the right pane of the UltraISO

Step 4. Preparing the USB flash drive to create a bootable operating system

In order to make the USB flash drive bootable, insert the device to the USB socket of your PC. Format it with the FAT32 file system. This is necessary so that your computer can read the data on the stick without any problems during the boot process because FAT is a universal system for storing /files and creating bootable disks on this stick.

  • If you do not know how to format your hard disk please refer to the above mentioned article.
  • Article on how to correctly format usb flash

Step 5: Write Windows distribution with UltraISO to flash

Luckily, UltraISO developers have already taken care of this, so you can use the appropriate entry "Self-Boot - Write Hard Disk Image" to write /files needed to create a bootable Windows 7 or 8 Flash. How to do that - see the screenshot below.

This command will help us make a bootable USB stick

Next, you will be asked how to create a bootable stick - select "USB-HDD+". If you have not formatted flash drive yet, you are suggested to perform it using UltraISO software. Again, do not forget that the disk must be formatted to FAT32 for full compatibility with your computer.

The last step is to select "Write Disk Image" or "Write". That is all you have to do to make a bootable USB stick! However, no: we just have to wait until the bootable stick creation is finished and test the resulting set on a working machine.

Step 6: Test the created bootable Windows distribution on the flash-drive

When you have finished the process of creating the boot-flash, enter Explorer or another file manager (e.g. Total Commander) and make sure the Windows OS /files are present on the flash-drive.

Next, reboot the computer and set the Windows 7 flash drive as bootable device in the BIOS. Then save your changes and verify that the computer starts using the flash drive, i.e. successfully loads the Windows shell.

Set this device as boot device in the BIOS

  • See also our guide on how to enable this device in the BIOS as boot priority

Resume . I hope you understand the principle to create a bootable flash using the easy tools of UltraISO. Of course, there are also other programs, methods to write Windows 7 distro to a USB stick, CD or DVD. Moreover, no one forbids using the latest versions of Windows - 8 and 10 - for similar purposes. In general, I wait for your questions in the comments. Share your experiences!

“Hello. My name is Kim. I discovered that technology, when used with a purpose, can be pretty amazing. To share the wonder of tech, I’ve written for blogs like and With over three years of freelance writing experience in the technology and entertainment niche, I can write a storm about a software app, a cool browser extension, a new mobile device and other geek-centric stuf... “

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Kim Barloso