Windows Longhorn build 4020

6.0.4020.idx02.030507-1155
	Build of Windows Longhorn
OS family	Windows NT
Version number	6.0
Build number	4020
Architecture	x86
Build lab	idx02
Compiled on	2003-05-07
Expiration date
Timebomb	+445 days after original install date
SKUs
	Professional
Product key
	CKY24-Q8QRH-X3KMR-C6BCY-T847Y
About dialog

Windows Longhorn build 4020 is a Milestone 5 build of Windows Longhorn. A screenshot of the build was shared on the BetaArchive Discord server on 27 November 2018. On 3 December 2018 this build was uploaded to the BetaArchive FTP server, along with build 4032.

Unlike other Longhorn builds, it was compiled in evaluation mode, and can be installed on the current date. Once the timebomb is triggered, Windows still functions, but a Windows Product Activation error message will show up that this build must be activated. Additionally, the timebomb is extended to 445 days, being one of the "Longhorn" builds that has the longest timebomb.

This build is mislabeled with a buildtag of "6.0.4020.idx02.030430-2218" in certain aspects of this build.

New features and changes[edit | edit source]

This build is very similar to build 4015 (main) and build 4017, however there are some minor changes:

Notably, the notifications appearance has been updated, which features a more sleeker design and the notification icon on the side now shows a reflection and bouncing up and down when hovered.
The Windows Explorer has been updated to no longer leak memory when the Windows Sidebar is enabled. WinFS also works in this build, just like in 4015.
The OOBE is now completely skipped; after the hardware portion of setup, the system logs on to the Administrator account. This was later returned in Windows Vista build 5259.
This build changes the "Longhorn XP" references to simply "Longhorn", such as in the desktop watermark. In build 4029 (main), it was renamed into onghornLay rofessionalPay (into Pig Latin strings).
Certain tiles, such as Windows Media Player, have been removed - while other new tiles got added.
MyTVApp now functions again - however there no longer is an Avalon Trust Manager pop-up, and it isn't as functional as before.
This is the earliest available build to include the Segoe UI font, which was also incorporated in post-reset builds of Longhorn and later Microsoft operating systems, albeit its regular version being named Segoe UI Book.

Setup[edit | edit source]

Although setup mostly resembles that found in the previous build, Setup now features a new page that includes options for initiating an upgrade or a clean installation. The minimum required version required to perform an upgrade installation is build 4000.

Hidden dialogs[edit | edit source]

There are a few dialogs that cannot be accessed normally. They are:

Security preferences - Allows the user to set preferences for security. It does not seem to have any effect.
Installer warning dialog - Asks for user's permission on whether to run an installer or not that is not trustworthy.
File resolve dialog - A new dialog that appears whenever a new file moves to a specific place where another file with the same name and file extension already exists.
Help and Support Center - There is an early version of the Help and Support Center in this build, it can be opened by running C:\Windows\HSX\helpplace.container.

Hidden sidebar tiles[edit | edit source]

There are a few sidebar tiles that are disabled by default in this build. They are:

RMA Test Tile - In this build, it only shows the title of the tile, and nothing else is there.
Longhorn Status - By default links to [1]
Messenger Status Tile - This tile only works with Windows Messenger. MSN Messenger can't be used with this tile. Also, this tile does not work with Windows Messenger 4.0, version 4.6 or 4.7 is required for it to function correctly.

Bugs and quirks[edit | edit source]

Installation[edit | edit source]

On some installs, once copying files has completed, setup will fail to create a boot.ini file. Although booting will still be possible, NTLDR will default to C:\WINDOWS.
The hardware detection portion of setup may crash, and an error message may appear as well. Simply press Alt+↹ Tab to access the error message, and click OK.
On some ISO files, the MBR, also known as the boot sector is corrupt.

Upgrading[edit | edit source]

On some machines when logging in after the first reboot when upgrading from Windows Longhorn build 4017 the system will bugcheck with the code 0x00000050.

Desktop Compositing Engine[edit | edit source]

This build includes two generations of the Desktop Compositing Engine. While the build is configured to use the new one out of box, initialization fails because milrender.dll is missing from C:\Windows\System32, to correct this the DLL must be copied from C:\Windows\I386. Additionally, sbctl.exe is required to control new DCE — this is not present in the build itself. Build 4029 (main)'s sbctl.exe can be patched to work with this early implementation.

First generation DCE in this build supports two variants: one is the full window transparency like in build 4015 (main) and build 4017 without a patched dce.dll; two is the glass-style frames identical to those in build 4015 (main) and build 4017 with a patched dce.dll. To utilize the older DCE implementation, the following must be done:

Import the following entries into the registry:

Windows Registry Editor Version 5.00

; Restores old DCE server
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Desktop]
"SBServers"=hex(7):64,00,63,00,65,00,2c,00,44,00,43,00,45,00,45,00,6e,00,74,00,\
  72,00,79,00,00,00,74,00,68,00,65,00,6d,00,65,00,73,00,72,00,76,00,2c,00,54,\
  00,68,00,65,00,6d,00,65,00,53,00,65,00,72,00,76,00,65,00,72,00,45,00,6e,00,\
  74,00,72,00,79,00,00,00,00,00

; Unhides DCE options in display settings
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Desktop\CompositingEngine]
"EnableShellUI"=dword:00000001
"Startup"=dword:00000002

; Configures window manager which in turn enables glass frames (optional). If left blank, DCE will use full window transparency
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Desktop\WindowManager]
"LocalWindowManager"="dce.dll,UxWmEntry"