Windows Longhorn build 4051

6.0.4051.idx02.031001-1340
Build of Windows Longhorn
Screenshot
Release nameWindows Longhorn Client Preview
OS familyWindows NT
Version number6.0
Build number4051
Architecturex86, x64, IA-64
Build labidx02
Compiled on2003-10-01
Expiration date
Timebomb+180 days after original install date
SKUs
Professional
About dialog
WindowsLonghorn-6.0.4051-About.png
TCB.png TCBGallery.png

Windows Longhorn build 4051 is a Milestone 7 build of Windows Longhorn, which was given out to attendees of Microsoft's Professional Developers Conference 2003 in Los Angeles, California, held between 27 and 30 October as a cut-down release from the demo builds shown off at that conference, making it one of the only two pre-reset Longhorn builds to receive a widespread release by Microsoft, with the other being the much more popular build 4074.

This build was compiled in x86, x64 and IA-64 variants, as well as evaluation mode, and as such, it can be installed on the current date. Attempting to log onto the desktop once the timebomb has been triggered will return the user to the login screen.

NFO files[edit | edit source]

The following NFO files were included as part of the Unknown[a] and WinBeta releases.

Unknown group

WinBeta

Editions and keys[edit | edit source]

Architecture Key
x86 & x64 TCP8W-T8PQJ-WWRRH-QH76C-99FBW
IA-64 P9BT8-6HBG3-GRF29-BM92B-M973D

Bugs and quirks[edit | edit source]

Shell[edit | edit source]

Due to the absence of the Avalon framework in the x64 and IA-64 compile, the Sidebar and Explorer preview pane are not present.

ClearType[edit | edit source]

Most copies of this build's x86 counterpart do not have ClearType font smoothing enabled by default.

TCP/IP stack[edit | edit source]

The TCP/IP stack can be unstable at times.

x64 build specifics[edit | edit source]

As Setup installs a barebone set of drivers by default, the x64 compile of this build suffers from major performance regressions and is subject to a number of bugs. Additionally, this build lacks a significant majority of the WoW64 compatibility layer, resulting in most x86-based applications not being able to function properly.

Hardware Abstraction Layer bugcheck on Checked/Debug compile[edit | edit source]

Attempting to boot the x64 checked/debug version of this build on a host device with the Hyper-V hypervisor enabled causes an exception within the Hardware Abstraction Layer's processor feature check, in turn triggering a 0x7E (SYSTEM_THREAD_EXCEPTION_NOT_HANDLED) bugcheck. This issue can be worked around by either substituting the hal.dll binary with the variant from the Free compile or by disabling Hyper-V (HypervisorLaunchType) from the host's boot configuration options.

Gallery[edit | edit source]

Setup[edit | edit source]

Miscellaneous[edit | edit source]

PDC 2003 discs[edit | edit source]

Notes[edit | edit source]

  1. The actual name of the group that leaked this build originally is still not currently known.