How-to create a bootable Windows 7 USB flash drive


You may be asking why you would want the ability to install Windows 7 from a USB flash drive. Here are a few reasons:

  • A flash drive is less likely to be damaged (scratched, broken, etc).
  • A flash drive is less likely to be lost in the growing pile of computer CD’s and DVD’s that you’ve amassed over the years.
  • A flash drive is less likely to be physically lost because they cost more than a CD/DVD and more care will be used.
  • Many smaller and/or cheaper computers do not come with a CD/DVD drive.
  • Installation from a flash drive will usually be quicker that from a CD/DVD drive.

All you need is a 4GB USB flash drive ($11 online), Windows 7 ISO image or DVD, WinRar, and a few minutes of your time.

Gather up the items needed before you start

Before we start let’s make sure we have our needed supplies!

  1. If you don’t have one already 4GB USB flash drives are available in a wide variety of styles. Any flash drive with a capacity of 4GB or more will work. You can find them at almost any chain store, but will find more choices and better prices at specialty stores.
  2. You will a need Windows 7 DVD or ISO image. If you do not have a DVD or ISO image you can download one from the following locations. Choose either 32 bit or 64 bit. Once downloaded follow the instructions in the January 15th newsletter to unlock.
  • Windows 7 Professional 32-bit download
  • Windows 7 Professional 64-bit download
  • Those who created the ISO previously, or just downloaded the ISO and followed the instructions from last issue, will need to extract the ISO to their hard drive. This may seem like an extra step, but working with the files on your hard drive will be much faster. It will also create a final unlocked USB drive that contains all editions of Windows 7.

    We will use WinRar to extract the ISO because it follows the ISO standard and respects the steps completed earlier to unlock the Windows 7 Editions. There are other programs that will extract ISO images, but they will undo any changes done when we created the edition unlocked ISO. Download WinRar. Click the Download Demo button on the right side (no need to purchase unless you want a great utility). On the next page skip the area labeled Step 1 or 2 (no need to enter your email address) and proceed directly to the Step 2 or 2 area on the web page. Click the blue download button. Choose to save or run the program. If you save the file install the program when the download is complete. The default settings should be sufficient for our needs.

  • Create a bootable Windows 7 USB flash drive

    Now that everything is in place let’s get to it!

    Extract the ISO files

    1. Locate your unlocked Windows 7 ISO and double click. This should cause WinRar to open and show the contents of the ISO. If it does not you will need to manually open WinRar and use File | Open Archive to navigate to the ISO and select it to open. WinRar will display the contents of the ISO file
    2. Click the Extract To icon and the following window will open.

      Notice that WinRar will extract the files to my desktop in a folder with the same name you gave your ISO image. Make sure yours shows a similar, easy to find, location. If it does not use the folder tree on the right to select a location where you can easily find the extracted files. Click OK at the bottom of the window.

    3. WinRar will open a window to show the progress as it extracts the contents of the zip file. Once it is finished the progress window will close. You can close WinRar. You should now have a new folder on your desktop containing the files!

    The following instructions may seem complicated, but if you follow along it is pretty easy! As always – some of these commands can have dire consequences if entered incorrectly. Backup your computer beforehand if you have doubts.

    Format the USB drive

    1. Insert your 4GB or larger USB flash drive into a USB slot on your computer. Windows will install drivers for the device. You should hear a tone and see a message indicating the USB drive is ready to use.
    2. Open My Computer (or Computer in Win 7) and note the drive letter of your flash drive. You will need this later so you may wish to write it down. In my case it is F.
    3. Right click on your flash drive and select Format.
    4. A new window will open. Change the highlighted areas to match the picture below then click Start.
    5. You will receive a warning that all data on the device will be lost. If you right clicked on the correct drive above click OK. If you are unsure click Cancel and return to step 6.

      Windows will begin formatting the USB drive. This will take a few minutes, so be patient.

    Use the Disk Partition tool

    NOTE: the diskpart utility is only available in Vista and Windows 7. XP users would need a third party tool such as MBRWizard and that method is not covered in this article.


    1. Next we need to open a command prompt with administrator privileges. Click the Start Orb in Vista or Windows 7. Type cmd in the search box. “cmd.exe” should be the top result. Right click on “cmd.exe” in the results and select Run as Administrator.

    2. A Command Prompt window will open with a flashing cursor. Type diskpart at the cursor followed by the Enter key. This starts the disk partition utility and displays DISKPART followed by a flashing cursor. Type list disk at the cursor followed by the Enter key.

      A list of disks will be displayed. As you can see above my flash drive is disk 2. Depending on how many drives you have in your computer this number will probably be “1”, but it could be different. It will be the smallest drive and probably listed in MB instead of GB. Note this number as you will need it later!

    3. At the flashing cursor type select disk followed by a space and the drive number from above. Press the Enter key.

      You will receive a confirmation message – Disk 2 is now the selected disk, however your number will be the number of your flash drive from above.

    4. At the flashing cursor type list partition followed by the Enter key. This will return a list of all partitions on the drive. There should only be 1 unless you have previously partitioned the drive.
    5. At the flashing cursor type select partition followed by a space and the number from above. In my case it is “1”. Press the Enter key.

      You will receive a confirmation – Partition 1 is now the selected partition. Type active followed by the Enter key. You will receive another confirmation – DiskPart has marked the current partition as active. Congratulations! You have just created an active boot partition on your flash drive.

    6. Type exit followed by the Enter key. This will exit the disk partition utility, but keep the command prompt open

    Make the USB drive bootable

    Next we need to make the folder containing the extracted Windows 7 files the working directory. If you look at the command prompt on your computer you will notice the cursor is flashing in front of “C:\Windows\system32>” making the system 32 folder inside the Windows folder the working directory. The easiest way to accomplish this is with the “cd” command.

    1. At the flashing cursor type cd.. (letter c – letter d – period – period) followed by the Enter key. You will see the working directory change to “C:\Windows>”. Once more type cd.. followed by the Enter key. The working directory will change to “C:\>”.
    2. Type cd followed by a space and the location of the folder containing the extracted Windows 7 files followed by the Enter key. Since you are currently at the “C:\>” prompt you do not need to enter that part. You can see an example on the third line in the above picture. If you are having problems use explorer to navigate to the folder containing the extracted Windows 7 files and use the address bar as a guide to show you what to type. My command was “cd users\david\desktop\win7 pro 64bit”.
    3. Type cd boot followed by the Enter key. This will change the working directory to the boot folder within the Windows 7 files.
    4. Type bootsect /nt60 followed by a space, the drive letter of the USB drive, and a colon. Use the drive letter you noted earlier when formatting. In my example I typed “bootsect /nt60 F:”. This command uses the files in the windows 7 folder to make the USB drive bootable.
    5. Since you have an explorer window open with the Windows 7 file go ahead and open another and navigate to the USB drive. Select all files in the Windows 7 folder and copy them (drag and drop or copy/paste) to the USB drive.

    You now have a bootable USB flash drive that will install any edition of Windows 7! I know it seems like a lot of work, but the fruits of your labor are worth it!. When you use this tool to install Windows 7 remember the BIOS of the computer needs to be changed so that USB is the primary boot device.

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    About the Author

    David Hartsock

    Executive Editor/Owner/Admin of Daves Computer Tips and all-around good guy - Dave's interest in computers began in the early 1980's during the Apple II era. In the early 1990's the PC began to replace proprietary and mainframe devices in Dave's industry so he began to learn and experiment with the PC. Through DOS, Windows 3.1, Windows 95, Windows 98, Windows 2000, Windows XP, Vista, Windows 7, Windows 8.1, and now Windows 10. Dave became the "go to" guy for friends, family, and coworkers with computer problems. Daves Computer Tips was born in 2006 in an effort to share these experiences with others in an easy to understand, plain English, form.

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