I need to write a windows7 iso file on my usb stick. I had been used to this task. I usually either use the dd tool, or unetbootin. Surprisingly both don't work today.

With dd I did the following :

dd bs=4m if='windows7.iso' of=/dev/sdb

My new supposedly bootable usb stick wont boot. Ok so I used unetbootin. This time, I get the unetbootin bootloader screen, but windows7 is not listed. Only the default choice is left.

In either way, I failed at creating my bootable stick. Few months ago, I could make this same USB stick boot with the very same ISO file. I also did the same tasks after formatting my stick withh this command:

mkfs.vfat -F 32 -I /dev/sdb

There were no difference as expected.

I am probably doing something wrong here, but I can't see where my mistake is.

Any idea on what is going on?

  • You can try cat or pv windows7.iso > /dev/sdb then sync. Always works for me.
    – sikerbela
    Apr 25, 2015 at 18:06
  • I don't know if it matters in this case, but one thing you are doing wrong is running mkfs on the whole disk, instead of a partition. USB sticks, like hard disks, usually need to be partitioned and then you put a filesystem in the partition.
    – psusi
    Apr 25, 2015 at 18:22

2 Answers 2


I'd consider trying it one more time, possibly with a fresh memory stick, including a "sync" prior to yanking it out (and are we sure that dd is case insensitive for the megabyte suffix? i use 'M' not 'm')

dd bs=4M if=windows7.iso of=/dev/sdb && sync

Plus the usual tedious suggestion about trying a different iso file (perhaps a linux one? ;) to test that your "windows7.iso isn't starting out corrupt (somehow)

  • Thank you for your answer. Yes most likely have to get a new version of my iso. It works wth all my other iso files except for this one.
    – kaligne
    Apr 26, 2015 at 14:11

Are you sure that this is the very same ISO you've used in the past? As far as I'm aware, Windows 7 ISOs are usually not hybrid images that can be dd'd to a USB stick like those available for many Linux distros, though Microsoft does provide a tool for downloading an image that can be burned to USB, which is probably the easiest method (if you have a Windows machine available to run the downloader).

If that's not an option, you may be interested in this slightly hacky way to trick unetbootin into creating a working bootable flash drive for Windows. It's been a few years since I've needed to do this, but your issue might be solved by making it write to an NTFS-formatted drive. (Remember to set the boot flag when partitioning.)

  • Thank you for your answer. I tried it but without success. It works with other iso files which means the one I need is probably corrupted.
    – kaligne
    Apr 26, 2015 at 14:12

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