How to create an .iso file out of a USB Recovery Drive

jimhoyle · 08 Oct 2018

I want to create an .iso file out of a USB Recovery Drive (a bit under 8 GB) I created. I want to do it because it was extremely slow (~2 h) to create the Recovery Drive and I also want to make a backup of the Recovery Drive in case both my C: corrupts and the USB stick corrupts.

I have already previously been successful at making an .iso file out of a USB Windows setup. Then with Rufus I wrote the .iso back to another USB stick and it worked, it booted perfectly. How I did that .iso file was with these instructions: Bootable Media and Images Preparation Guide with How-to Approach starting from section 2.2's UEFI part. It worked, but it has X:\EFI\Microsoft\boot\efisys.bin as the Boot Image. However, the Recovery Drive has no such file.

What is the correct way to make a working .iso out of a Windows 10 USB Recovery Drive? Or can I just simply copy the files to any USB stick and then add a boot sector or something?

xTL · 08 Oct 2018

Hello Jim, you could try this, it should do the trick.
https://www.alexpage.de/usb-image-tool/

Bree · 08 Oct 2018

xTL said:

Hello Jim, you could try this, it should do the trick.
https://www.alexpage.de/usb-image-tool/

Yes, I've used that too. It doesn't make an ISO that can be burned to a DVD, but it's great for making a .img file that can be restored to another usb.

However, a usb copy of the Windows 10 recovery drive or the Windows install usb can easily be made just by copying all the files and folders to another usb. It must first be formatted as Fat32. The partition needs to be marked as Active if you want it to boot on a legacy system as well as a uefi system.

jimhoyle · 09 Oct 2018

Bree said:

Yes, I've used that too. It doesn't make an ISO that can be burned to a DVD, but it's great for making a .img file that can be restored to another usb.
However, a usb copy of the Windows 10 recovery drive or the Windows install usb can easily be made just by copying all the files and folders to another usb. It must first be formatted as Fat32. The partition needs to be marked as Active if you want it to boot on a legacy system as well as a uefi system.

Great, thanks! Could you explain even further so that I understand how the booting USB works? Does either legacy or UEFI actually boot by just copying the files on an empty FAT32 USB (not even marking as Active)?

Bree · 09 Oct 2018

A legacy system will only try to boot from a partition that is marked Active. A uefi system doesn't care. Some bootable USBs, notably Linux Live USBs cannot be copied in this way, but for the Microsoft recovery usb or the windows install usb justs copying the files and marking the partition Active is sufficient.

I routinely make Windows 10 install USBs by downloading the ISO file, mounting it then copying its contents to a USB. I first prepare the USB using Diskpart commands. To prepare the USB, use Diskpart. In this example the USB is disk 1, use LIST DISK first to find the number of yours.

Code:

Microsoft DiskPart version 10.0.16299.15 Copyright (C) Microsoft Corporation.

DISKPART> LIST DISK

  Disk ###  Status         Size     Free     Dyn  Gpt
  --------  -------------  -------  -------  ---  ---
  Disk 0    Online          465 GB      0 B
  Disk 1    Online         7634 MB      0 B

DISKPART> SELECT DISK 1
Disk 1 is now the selected disk.

DISKPART> CLEAN
DiskPart succeeded in cleaning the disk.

DISKPART> CREATE PARTITION PRIMARY
diskPart succeeded in creating the specified partition.

DISKPART> SELECT PARTITION 1
Partition 1 is now the selected partition.

DISKPART> FORMAT FS=FAT32 QUICK
  100 percent completed
DiskPart successfully formatted the volume.

DISKPART> ACTIVE
diskPart marked the current partition as active.

How you boot from a USB depends on the specific make/model of PC. For most there is a function key, often F12, you can press at start up to give you a menu to choose which device to boot from. Check your manual for details. When you boot from an MS boot usb a boot.wim windows image file is loaded from the usb into memory as a virtual drive and the windows setup runs from this, usually as the X: drive.

xTL · 09 Oct 2018

Bree said:

Yes, I've used that too. It doesn't make an ISO that can be burned to a DVD, but it's great for making a .img file that can be restored to another usb.

However, a usb copy of the Windows 10 recovery drive or the Windows install usb can easily be made just by copying all the files and folders to another usb. It must first be formatted as Fat32. The partition needs to be marked as Active if you want it to boot on a legacy system as well as a uefi system.

yea i know it makes .img :P
but you can change the .img extension to .iso and it will work :)

spapakons · 09 Oct 2018

New Rufus (version 3.x) has a Save icon next to the USB Flash drive which can be used to create an ISO image of the drive. You can also try Transmac which creates a DMG (Mac OS compatible disk image) out of the drive.