7z

pkg install p7zip

doas chmod 666 /dev/da0

doas VBoxManage internalcommands createrawvmdk -filename win7usb.vmdk -rawdisk /dev/da0

doas chown erikn:erikn win7usb.vmdk

chmod 660 win7usb.vmdk

dd if=/dev/zero of=/dev/da0 bs=16m count=1

win7usb.vmdk

cmd.exe

Code: diskpart list disk select disk n (where n is the number of your USB drive) clean create partition primary active format fs=fat32 quick assign exit

Code: cd d:\boot\ .\bootsect.exe /nt60 e:

win7usb.vmdk

rm win7usb.vmdk

sync

Code: doas chmod 666 /dev/da0s1 mkdir -p ~/tmp/win7usb/ mount_msdosfs /dev/da0s1 ~/tmp/win7usb/

cd ~/tmp/win7usb/

7z x /var/tmp/en_windows_7_professional_with_sp1_x64_dvd_u_676939.iso

sync

umount ~/tmp/win7usb/

rmdir ~/tmp/win7usb

vslash, I followed your steps for the most parts, but I modified it a bit to save a little time since presumably writing the ISO to the USB memory stick through VirtualBox will give USB 1.0 speeds or slower.You'll need VirtualBox and a Windows 7 VM for the first set of steps. https://www.freebsd.org/doc/handbook/virtualization-host-virtualbox.html For the last set of steps you will need thecommand from p7zip. (as root if you don't have it.)1. Plug USB drive or key into computer and ensure it's not mounted, unmount if it is.2.3.4.5.6.7. Attachto a Windows 7 VM.8. Boot VM.9. In VM usingas you said,10. The USB disk is E:11. Mounted ISO on VM. The ISO appears as D:12. Using PowerShell as Administrator,So up until this point I did pretty much exactly the same thing that you did but now I do something different.13. Shut down the VM and detachfrom VM.14.15.16. Unplug the disk and plug it back in.17. Mount it unless you have an automounter that has already done so for you.18.19.as suggested by Ogham mentioned above that 7-zip is able to extract UDF but it's important to use "x" extraction which will preserve full paths, not "e" extraction as Ogham wrote, as "e" flattens the structure and puts all files directly in the target directory.20.21.22.Enjoy bootable USB stick.