I have an ISO image of the Windows 7 installation DVD, but I can't burn it to CD or DVD. I have an empty flash drive with plenty of space. Is there any way I can put the ISO image on it and install from it as if it were a CD?


Microsoft has released a tool to put an ISO of Windows 7 on a bootable USB drive (or on a DVD).

Windows7Hacker has an explanation on where to download this tool and how to use it : Creating Bootable Windows 7 Install USB Flash Drive or DVD Using Windows 7 USB/DVD Download Tool

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    Do you happen to know if one can install Grub2 loader to USB after creating this bootable USB? Would be nice to have a possibility to run Live Linux or install Windows. – dma_k May 22 '14 at 19:50
  • @dma_k I'm sure it's possible. Haven't tried it, but you should be able to extract the bootloader from the iso and chainload it with GRUB. – Anonymous Apr 2 '17 at 19:06
  • Actually after I've created Windows installation flash, I've copied its' contents to Grub flash and used ntldr /bootmgr in config. It worked as a charm. – dma_k May 18 '17 at 23:07


Easiest way is to mark a partition as active (although not always needed, depending on your motherboard).

Next, extract everything in the ISO to the root of the USB drive (use Winrar, 7-Zip or your favourite extraction program.).

Reboot and either change boot order in the BIOS or press whatever key it is on your motherboard to bring up the boot menu (usually F12 or Esacpe).

Choose USB drive.


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    Can you just quickly mention how to mark a USB drive partition as "active"; I've not heard of that before. – Neil Barnwell Jul 19 '10 at 11:21
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    @Neil Barnwell, you simply go to disk management or any partition management tool and just set the drives partition to active in the same way as you would a hard drive. In Windows disk Management, right click and choose Active. – William Hilsum Jul 19 '10 at 12:29
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    Your solution doesn't address making sure a proper boot sector exists on the USB key, which I believe is necessary for it to boot. @Matthew Read's solution does address this. – LawrenceC Jun 24 '11 at 16:15
  • Unfortunately, to us mere mortals, "marking a partition as active" is somehow not easy...as it were :) – rogerdpack Apr 8 '16 at 23:19

Use UNetBootin to create a bootable USB flash drive with the ISO.

The software was made for creating bootable linux flash drives, but works with any bootable ISO.

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  • Doesn't detect my Transcend 250GB external HDD :( – Bogdan0x400 Jun 24 '11 at 15:36
  • @Bogdan0x400, open the command prompt, cd to the folder where unetbootin.exe is located and start it with the option "targetdrive=f:" unetbootin targetdrive=f:" (replace "f:" with your drive's letter) – sm4rk0 Feb 20 '13 at 0:24

Here you go, in four easy steps:

  1. Using the HP USB Disk Storage Format Tool (v2.0.6), format the flash drive using FAT32 leaving all the boxes unchecked.

  2. Mount the Windows 7 ISO image using Virtual CloneDrive (a free tool).

  3. Then copy the contents of the ISO image (all of the Windows 7 files and folders) over to the flash drive. Grab a cup of coffee; it could take upwards of 5-10 minutes.

  4. Lastly, rename the file on the root of the flash drive from "BOOTMGR" to "NTLDR".

I hope this helps...

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    Almost a copy of my answer, anyway - I don't think step 4 is needed - I have never needed to rename anything and I do not recommend step 2. Any sort of Virtual drive program installs a driver which will always be running and slow your machine (although not exactly by a lot, and I do like virtual clone drive). If this is a one off job, it is much better just to use Winrar or 7 zip as I said. It will dothe same job and will not do anything to the system. – William Hilsum Oct 28 '09 at 20:48
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    I don't understand how it is almost a copy of your answer, anyway - thanks for the critique... lol – pjemmert Oct 28 '09 at 20:58

I know this question is a few years old, but I think this program is worth mentioning (it's also easy).
Your Universal Multiboot Integrator
YUMI Multiboot USB Creator
You can use it to add many Operating Systems on one flash drive (both Windows and Linux, I don't know about MAC OSX) You can also use it to add other ISO images, like Norton Ghost SRD, Acronis True Image and many other tools. YUMI list of available ISOs!

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  • Windows only :| – rogerdpack Jan 12 '19 at 23:54

If already running Windows™ you can simply use the Windows 7 USB/DVD Download Tool from Microsoft.

If on another OS you can perform the following steps:

  1. Make sure the filesystem is NTFS and has the bootable flag set..
  2. Use ms-sys to write boot record (ms-sys -7 /dev/sdx).
  3. Mount the ISO and copy all the files and directories.
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I love using rufus for extracting any OS onto a USB. It's source is on github as well. For windows:

Rufus Source on GitHub

Rufus UI

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