How to make Windows 7 USB flash install media from Linux?

OK, after unsuccessfully trying all methods mentioned here, I finally got it working. Basically, the missing step was to write a proper boot sector to the USB stick, which can be done from Linux with ms-sys or lilo -M. This works with the Windows 7 retail version.

Here is the complete rundown again:

Install ms-sys - if it is not in your repositories, get it here. Or alternatively, make sure lilo is installed (but do not run the liloconfig step on your local box if e.g. Grub is installed there!)

Check what device your USB media is assigned - here we will assume it is /dev/sdb. Delete all partitions, create a new one taking up all the space, set type to NTFS (7), and remember to set it bootable:

# cfdisk /dev/sdb   or   fdisk /dev/sdb (partition type 7, and bootable flag)

Create an NTFS filesystem:

# mkfs.ntfs -f /dev/sdb1

Write Windows 7 MBR on the USB stick (also works for windows 8), multiple options here:

1. # ms-sys -7 /dev/sdb
2. or (e.g. on newer Ubuntu installs) sudo lilo -M /dev/sdb mbr (info)
3. or (if syslinux is installed), you can run sudo dd if=/usr/lib/syslinux/mbr/mbr.bin of=/dev/sdb

Mount ISO and USB media:

# mount -o loop win7.iso /mnt/iso
# mount /dev/sdb1 /mnt/usb

Copy over all files:

# cp -r /mnt/iso/* /mnt/usb/   ...or use the standard GUI file-browser of your system

Call sync to make sure all files are written.

Open gparted, select the USB drive, right-click on the file system, then click on "Manage Flags". Check the boot checkbox, then close.

...and you're done.

After all that, you probably want to back up your USB media for further installations and get rid of the ISO file... Just use dd: # dd if=/dev/sdb of=win7.img

Note, this copies the whole device! — which is usually (much) bigger than the files copied to it. So instead I propose

# dd count=[(size of the ISO file in MB plus some extra MB for boot block) divided by default dd blocksize] if=/dev/sdb of=win7.img

Thus for example with 8 M extra bytes:

# dd count=$(((`stat -c '%s' win7.iso` + 8*1024*1024) / 512)) if=/dev/sdb of=win7.img status=progress

As always, double check the device names very carefully when working with dd.

The method creating a bootable USB presented above works also with Win10 installer iso. I tried it running Ubuntu 16.04 copying Win10_1703_SingleLang_English_x64.iso (size 4,241,291,264 bytes) onto an 8 GB USB-stick — in non-UEFI [non-secure] boot only. After execution dd reports: 8300156+0 records in 8300156+0 records out 4249679872 bytes (4.2 GB, 4.0 GiB) copied, 412.807 s, 10.3 MB/s

Reverse if/of next time you want to put the Windows 7 installer onto USB.

You can accomplish this with dd, if your PC supports UEFI, and, by extension, GPT disks.

Open up a terminal, your going to need to find what device is your pendrive. If you have the drive mounted you can find the name of the device by typing "mount" and looking at it's entry. Something like the following:

/dev/sdb1 on /media/USBDISK type vfat (rw,nosuid,nodev,uhelper=hal,uid=1000,utf8,shortname=mixed)

In this case the first partion of /dev/sdb is mounted at /media/USBDISK. Open a root shell and unmount the drive.

umount /dev/sdb1

Go to the directory where your ISO is stored in a root shell and type in the following: (Replace windows7.iso with whatever the iso is called, and /dev/sdb with the device id of your usb stick).

dd if=windows7.iso of=/dev/sdb

If your motherboard supports booting off of a pendrive it should be able to boot off it. This will get the installer on the pendrive not the OS itself.

PCambell's suggestion is good but you will also want to clear the MBR, the linux equivalent is below

I tried this and it worked (I'm not sure why the dd method failed but seems the partition had to be ntfs?):

• work out which /dev/device is your usb flash drive and unmount it
• clear the MBR: dd if=/dev/zero of=/dev/device bs=446 count=1
• run fdisk /dev/device
• remove all partitions and create 1 primary partition, make it bootable then save the changes
• run mkfs.ntfs /dev/device1 (partition 1)
• copy the entire contents of the windows install iso on to the partition you created

Instead of

dd if=windows7.iso of=/dev/sdb

you write as root,

dd if=windows7.iso of=/dev/sdb1 

(ADD 1 at the end or whatever your USB drive is placed at.)