Windows 10 build 10586.1078 (th2_bnb_arm64)

10.0.10586.1078.th2_bnb_arm64.160124-1800
	Build of Windows 10 November Update
OS family	Windows NT
Version number	10.0
Build number	10586
Build revision	1078
Architecture	ARM64
Build lab	th2_bnb_arm64
Compiled on	2016-01-24
Expiration date
Timebomb	2016-07-15 (+173 days)
SKUs
	RT (CoreARM)
About dialog

Windows 10 build 10586.1078 (th2_bnb_arm64) is an internal post-RTM build of Windows 10 November Update, which was found on a Qualcomm Snapdragon 810 (MSM8994) Large Interface Qualcomm User Interface Device (LIQUID) Reference Platform.

Several screenshots depicting the full build's CoreARM edition running under the QEMU emulator were shared on 2 February 2025, with the kernel binaries and the full Windows Recovery Environment being shared publicly on the same day. The full build was later shared on 17 February 2025.

This build notably features an early version of the x86-to-ARM (XtA) JIT compiler, which allows running certain x86 applications, and is the earliest known client build of Windows on ARM64 to feature the full desktop experience.

Unlike most other Windows 10 November Update builds, this build uses test code signing and as a result can be booted on the current date.

Installation[edit | edit source]

QEMU installation guide:

Prerequisites[edit | edit source]

The following requirements used in order to install this build onto a virtual machine are listed below:

A 64-bit version of QEMU
A version of the TianoCore EDK II firmware for ARM64 emulation, to be placed in the QEMU installation directory under fw/QEMU_EFI.fd
The Red Hat VirtIO driver package
Virtual hard disk image for OS install

Instructions[edit | edit source]

Create the needed virtual disk images through the diskpart utility by running the below script; they will be created under a directory in the C: drive named 10586ARM64. The partitions it will contain will be respectively mounted under drive letters P and Z.

create vdisk file="C:\10586ARM64\HDD.vhd" maximum=65536 type=expandable
select vdisk file="C:\10586ARM64\HDD.vhd"
attach vdisk
convert gpt
create partition efi size=100
format quick fs=fat32
assign letter=Z
create partition primary
format quick fs=ntfs
assign letter=P
exit

Deploy the WIM image, mount the VirtIO driver disc image, install the Windows 10-specific VirtIO storage driver by invoking the following DISM commands and add the boot files to the EFI partition:

rem Apply the image and install the VirtIO storage driver (both install_NoCustomizations.wim and install_WithCustomizations.wim will work fine)
DISM /Apply-Image /ImageFile:"X:\path\to\install_NoCustomizations.wim" /ApplyDir:P:\ /Index:1
DISM /Image:P:\ /Add-Driver /Driver:"Y:\viostor\w10\ARM64\viostor.inf"

rem Make system bootable
bcdboot "P:\Windows" /s Z: /f UEFI

Eject the currently attached virtual disk from the machine, then paste and run the contents of the below script onto a batch file within the QEMU installation directory:

set MAIN="C:\10586ARM64\HDD.vhd"

qemu-system-aarch64 ^
    -M virt,highmem=false -cpu cortex-a72 -smp cores=4,threads=2 -m 2048 ^
    -device qemu-xhci -device usb-kbd -device usb-tablet ^
    -hda %MAIN% ^
    -bios fw\QEMU_EFI.fd -device ramfb ^
    -rtc base=2016-01-24,clock=vm ^
    -device intel-hda -device hda-output ^
    --accel tcg,thread=multi

Bugs and quirks[edit | edit source]

Recovery Environment[edit | edit source]

The Recovery Environment launcher (RecEnv.exe) is broken and will crash out with an error in this build. It is possible to bypass the error by modifying winpeshl.ini in the WinRE image to point to the Command Prompt (X:\Windows\System32\cmd.exe), which will make it act more like a WinPE by launching the Command Prompt instead of the broken recovery tools.

Readme[edit | edit source]

The build was shared along with the following readme:

Readme

10.0.10586.1078 (th2_bnb_arm64.160124-1800) arm64fre CoreARM

Sourced from a Qualcomm Snapdragon 810 LIQUID (Large Integrated Qualcomm User Interface Device) Reference Platform.
EFI revision: UEFI_PW.WIN.3.1.1527031.100089.M8994AAASFNEZA100089 - 64b Jul 13 2015 05:58:07

Notes written by pivotman319. This was a preservation effort led by a team of nine:
- Orangera1n;
- amarioguy;
- Jimkoutso;
- Mainnn;
- pivotman319;
- Scamdisk;
- Guramovich;
- Osmium, and;
- WitherOrNot

Special credit goes to gus33000 for helping dump this amazing gem and explaining what needs to be cleaned up before release

There are two versions of this build: one with the absolute original components (from the dump itself, including the x86-to-ARMv8 and Cobalt translation layers - install_NoCustomizations.wim), and another with all additions mentioned below (install_WithCustomizations.wim). Besides that, it is otherwise 1:1 functionally identical to Threshold 2 RTM.

Includes the following additions:
	- MSM8994 SoC platform drivers, SBL1 boot blocks from eMMC
	- Features a Windows SKU that was deprecated in the source tree and was no longer being actively developed by 2014 (Microsoft-Windows-CoreARMEdition/Windows RT 8.1)
	- Early functioning versions of the x86-to-ARM and Cobalt (ARMv7) instruction translation layers (based off of Connectix Virtual PC PPC JIT code) [*1/*2]
	- Full WoW64 subsystem built into OS [*1]
	- .NET Framework 4, [*1] Common Language Runtime [*1/*3]
	- Private builds of Windows Update client engine, AppX deployment server, AppX deployment utilities and an internal script for slipstreaming a small subset of Windows inbox applications targeting ARMv7 from build spew
	- Debugging symbols for Windows OS core, AppX and WoW64 libraries with full type data
	- AppX Test Root Certificate (expires on 1/1/2050)
	- A small subset of inbox applications and some third-party applications downloaded from the Windows Store for XtA testing purposes
	- ARMv8 WinDbg distro with internal debugger extensions

Due to technical limitations in the Windows servicing stack, the original AppX packages for this build cannot be properly re-provisioned into the latter image. As a result, the "WindowsApps" directory from the original eMMC dump has been provided in the "extras" directory for your convenience.

To install the inbox applications:
	- Enable AppX sideloading (via the development mode toggle in Settings or line-of-business enablement/APPXLOB);
	- Install the provided AppX test root certificate in the System32 directory into the Trusted Root Certification Authorities machine store, and;
	- use PowerShell commandlet Add-AppxPackage or (Min)DeployAppX to install the inbox applications

Remember to install the provided Visual C++ and .NET runtimes in the WindowsApps directory before installing anything else first. You may use the provided (Min)DeployAppX executable to install these applications while the OS is running; documentation is provided within the tooling itself.

Footnotes:
	*1: Not present in ServerARM64 builds from the same time period
	*2: Cobalt translation layer is provided via a separate Windows SxS package only made available to Qualcomm partners (Microsoft-Windows-WowPack-CoreARM-arm64arm-Package)
	*3: PowerShell does not run as some parts of the .NET CLR are missing