Windows Longhorn build 4086 (Lab01_N)

6.0.4086.Lab01_N.040704-2000
Build of Windows Longhorn
6.0.4086.Lab01_N.040704-2000
OS family
Architecturex86
Compiled2004-07-04
Timebomb2004-12-31 (+180 days)
Works in
About
WindowsLonghorn-6.0.4086-lab01-About.png
SKUs
Professional
Key
TCP8W-T8PQJ-WWRRH-QH76C-99FBW
TCB.png

Windows Longhorn build 4086 (Lab01_N) is a Milestone 7 build of Windows Longhorn. On 23 January 2020, this build was listed on a thread by UX.Unleaked blog founder Grabberslasher to be released to the BetaArchive FTP, and was later released in the tenth set of their 33 Longhorn/Vista builds on 2 February 2020 with its other compiles.[1]

Changes[edit | edit source]

  • This build reintroduces the new Windows Error Reporting dialog from build 4074 after being absent from previous componentized builds, although it is only displayed for Avalon-based programs (as a blank crash dialog) or when installing a driver (as a driver package installation error dialog).

Bugs and quirks[edit | edit source]

Installation[edit | edit source]

  • As typical of builds in this build range, it tends to take a long time to install and can be unstable.
  • Various commands in WinPE's command prompt such as formatting a drive will not work due to VSSAPI.DLL being missing.

Upgrade[edit | edit source]

Attempting to upgrade from other builds is not possible as one of two outcomes may occur:

  1. A bugcheck with error code 0x7E after the second reboot. This is commonly observed when trying to upgrade from non-componentized builds, such as 4074 (via a registry tweak that reports it as a componentized build).
  2. An error during the file copy phase.

WinPE[edit | edit source]

  • The mouse driver in this build's WinPE does not function on specific hardware configurations or hypervisors, and may require a keyboard to navigate through the installation procedure. This issue appears to be largely related to using a PS/2 mouse, as most ordinary USB mice appear to function properly in setup.

Timebomb[edit | edit source]

Unlike other Longhorn builds, it contains a broken timebomb and can be installed on the current date. However, before installation, machine time will still be checked and verified.

WordPad[edit | edit source]

WordPad does not start, as it will display with Failed to create empty document instead.

Outlook Express[edit | edit source]

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

Themes[edit | edit source]

  • The Windows Classic theme does not function due to a broken Windows Classic.theme file.

Explorer[edit | edit source]

  • CD and DVD drives behave like local disks.
  • Help and Support crashes Explorer.
  • Explorer will crash after adding the display tile in sidebar and won't launch again. A workaround is to create a new account via cmd.
  • When the Aero taskbar and sidebar are enabled, the Taskbar erroneously uses the Sidebar background.

Control Panel[edit | edit source]

  • Hardware and Devices folder does not open.
  • By default, the Phone and Modem Options Control Panel applet name is empty.
  • Computer Management displays script errors due to missing registry entries.

Graphics[edit | edit source]

On some computers, you will need to enable VGA Mode after installing video drivers or the system will result in a blue screen of death with a error code 0x000000B4.

Driver installation[edit | edit source]

When you install a driver, a driver package installation error dialog may appear. Just click on Cancel to continue the driver installation.

Windows Product Activation[edit | edit source]

Windows Product Activation is missing.

Safe mode[edit | edit source]

The Safe mode is completely broken and results in a bugcheck with code 0x0000007B. This is because the Safeboot key, located in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control is largely incomplete and missing a lot of entries. Restoring the key from an earlier build with working safe mode allows this build to boot properly, but the video driver will not initialize properly. As a result, the operating system will freeze as it transitions into graphical mode, so Safe Mode is currently not known to work on these pre-reset Longhorn componentized builds.

Gallery[edit | edit source]

References[edit | edit source]