Windows Longhorn build 4081

Windows Longhorn build 4081 is a Milestone 7 build of Windows Longhorn. On 23 January 2020, this build was listed in a BetaArchive thread by UX.Unleaked blog founder Grabberslasher. This build was released on 27 January 2020 in the fourth set of his 33 Longhorn/Vista builds along with build 5098.

Changes

 * This build is identical to build 4074, but this build is the first componentized build of Longhorn, meaning many core features from previous builds have been removed and introduced several bugs. These features were scheduled to be added in subsequent versions of the operating system, leaving what remains the bare minimum to run the system.

Setup
Setup is very similar to the previous build of Windows Longhorn, but with a bit updated Setup UI.

Installation
As typical of builds in this build range, it tends to take a long time to install and can be unstable.

No mouse driver in WinPE
On some computers and virtualizers, the WinPE doesn't support the mouse, so you must use the keyboard to navigate the WinPE. This seems to be related to using a PS/2 mouse, as USB mice seems to work fine for the setup.

WordPad
WordPad does not start, as it will display with   instead.

Outlook Express
Outlook Express does not start due to registry errors and certain dependencies on WinFS.

Themes

 * The Windows Classic theme will not function due to a broken  file.

Explorer

 * CD and DVD drives behave like local disks.
 * Help and Support crashes Explorer.
 * Explorer can randomly crash for no reason under normal use, such as adding Sidebar tiles, but this depends on the hardware being used.

Control Panel

 * Hardware and Devices folder does not open.
 * Sounds Control Panel applet is missing.
 * Task Scheduler from Control Panel shows a nameless folder and generic folder icon.
 * Phone and Modem Options Control Panel applet name is empty.
 * Computer Management displays script errors due to missing registry entries.
 * Device Manager has a bug and as such, you cannot update drivers. You can install drivers by using devcon from the Windows XP DDK.

Creating folders
The folder creation bug from build 4074 is still present in this build. You can apply a registry key by the following:

DirectX
Although the Desktop Window Manager is present and can be activated by pressing Ctrl + Shift + F9 as in Windows Server 2008 build 4066, it will black screen due to a broken DirectX installation. It can fixed via the instructions listed on the Windows Aero page.

Graphics
Enable VGA Mode after installing video drivers or the system will result in a blue screen of death with a error code.

Windows Product Activation
Windows Product Activation is missing.

Safe mode
The safe mode is completely broken and results in a blue screen of death.