Windows Longhorn build 4086 (lab03_dev)

6.0.4086.lab03_dev.040629-1910
Build of Windows Longhorn
6.0.4086.lab03_dev.040629-1910
OS family
Architecturex86
Compiled2004-06-29
Timebomb2004-12-26 (+180 days)
Works in
About
WindowsLonghorn-6.0.4086-lab03-About.png
SKUs
Professional
Key
TCP8W-T8PQJ-WWRRH-QH76C-99FBW
TCB.png

Windows Longhorn build 4086 (lab03_dev) 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 his 33 Longhorn/Vista builds on 2 February 2020 with its other compiles.[1]

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.
  • Partition and format a drive from a previous or later build prior to starting installation.

No mouse driver in WinPE[edit | edit source]

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.

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.

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 will 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.

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]

Enable VGA Mode after installing video drivers or the system will result in a blue screen of death with a error code 0x000000B4.

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 0x7B. 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 a build with working safe mode enables this build to boot in safe mode, but the display is not initialized properly which leads to no video output (which is seen as a black screen).

Gallery[edit | edit source]

References[edit | edit source]