HELP! : How to image a Windows Surface RT (ARM)

You can't boot any other OS than Windows RT on those ARM devices. Microsoft have made sure that the secure boot will stay on at all times. There have been some successful attempts in the past at disabling the secure boot (e.g. this discussion - https://forum.xda-developers.com/windows-8-rt/rt-development/disabling-secure-boot-surface-rt-t3360721), however all those security holes have been patched by Microsoft.

If it is a fully up to date Windows RT 8.1 device, your chances of booting any other OS are very, very slim. Even if you would suceed, you would need an OS that can run on an ARM CPU, and some custom drivers most likely D

Tic-Tac is right, as far I know there's no solution to boot with a Linux distro on a Windows Surface RT (ARM).

For the Surface tablet with Windows RT 8.0 there is a possibility to Jailbreak it and then launch unsigned software, for example an x86 emulator or an ARM-compiled unsigned software in order to make a forensic copy.

For the Windows RT 8.1 there's currently no possibility to jailbreak the device but there is a method to image the logical volumes of the device by using DISM.

* First you need to have an access to the system, in other words you have to log into the system. If you don't have the user password, you must find a way to find it.
* When you are logged in the system, you need to generate the bitlocker-key. These devices are automatically protected with bitlocker when you register the system the first time with your Windows live account.
* You'll need the key to unencrypt your image file.

* Then, when the OS is booted, hold on the left shift-key and click on reboot
* You should see the advanced options menu
* Click on Troubleshoot – > Advanced Options – > Command prompt
* If everything's worked fine a command prompt should appear. That's it, now you can use the command dism to make a volume disk image.
* If needed you can use diskpart to assign a letter to the hidden volumes/other partitions.
* Use the command Diskpart – > list volume – > select volume X – > assign letter=X
* Ok now that every volume is assigned, now you can use the command dism

dism /capture-image /imagefileX\"yourimagefile".WIM /capturedirc\ /namewinrt

/imagefile choose the path and the name of the file you want to create
/capturedir choose the volume you want to copy
/name choose a label

* Now that the primary volume is copied, you can append the hidden volumes to your image.
* Use the command

dism /append-image /imagefileX"yourimagefile" /capturedird\ /namesystem

* You have now a .wim file !
* Copy your Wim file on your work computer.
* Open a command prompt and use the dism command again.
* You need to "mount" your file to extract the files on your computer.
* First type

dism /get-wiminfo /wimfileX"path to your wim file"

* Normally you should see the different partitions that you have imaged, each one corresponding to an index.
* Type now the following command

"dism /mount-wim /wimfileX"path to your wim file" /indexX /mountdirX\path to extract the files"

/index choose the number of the index (volume) you want to extract
/mountdir choose the directory where to extract the files

* Once finished to unmount type the following command dism /unmount-wim /mountdirX"path to your wim file" /discard