Windows Longhorn build 4085 (Lab07_N)

Build of Windows Longhorn
OS familyWindows NT
Version number6.0
Build number4085
Build labLab07_N
Compiled on2004-06-09
Expiration date
Timebomb2004-12-06 (+180 days)
Product key
About dialog

Windows Longhorn build 4085 (Lab07_N) is a Milestone 8 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 fifth set of their 33 Longhorn/Vista builds on 28 January 2020, alongside build 4050 (idx02).[1]

Fixes[edit | edit source]

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.

WordPad[edit | edit source]

WordPad does not start, as it will display 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 style cannot be applied as there are no color schemes defined in the registry. This can be fixed by using a registry modification.

Explorer[edit | edit source]

  • CD, DVD and floppy drives appear and behave like local disks.
    • As a result of this, the system continuously throws out notifications about low disk space.
  • 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 Command Prompt.
  • 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]

Enable VGA Mode after installing video drivers or the system will bugcheck with error code 0x000000B4.

Windows Product Activation[edit | edit source]

The Windows Product Activation component is missing due to the componentization. An incomplete rewritten one in .NET-managed code and Avalon would be reintroduced in build 4093.

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]