Windows Longhorn build 4074

From BetaWiki
Jump to navigation Jump to search

Build of Windows Longhorn
OS family
Architecturex86, x64, ia64
Timebomb2004-10-23 (+181 days)
Works in
LH4074 Winver.png
TCB.png TCBGallery.png

Windows Longhorn build 4074 is the official WinHEC 2004 preview build, which leaked in 2004-05. This build is a Milestone 7 build of Longhorn and the most famous build of Longhorn as it was distributed publicly. This build comes in multiple architectures, being x86, amd64, and ia64.

This build is the first to default with the Segoe UI font that would be used by default in later Windows operating systems. Many icons from Windows XP were replaced with new, high-resolution versions, as with build 4066. While the Slate theme is still present, it also contains the new Jade theme that is also present in build 4066. The default wallpaper has also been changed to "Leaves". The Jade theme also enables native Aero transparency, which has not been seen since build 4042 (however, full transparency will require you to put on the Desktop Window Manager and have the window small; if the window is maximized, then it will be opaque).


Many features that were present in earlier builds have been removed or hidden in this build. As a result, the features that remained were improved, which include:

  • Complete DWM Aero Effects - This build, unlike many other leaked builds, is the first build to have complete Aero effects in Explorer and Internet Explorer. However, a registry modification is required to extend the effect into the full UI of Explorer and Internet Explorer. The green translucent effect is used natively in this build instead of transparent "Glass". Modification is further required to replace the translucent borders with glass. On how to enable Aero transparency, go here.
  • Aero Stars - An animated desktop which shows stars bouncing around the screen.
  • Improved Preview and Filter Panes - This build has these panes improved, especially the Preview Pane, which is more functional than its leaked server counterpart, build 4066.
  • Animated Preview Pane Aurora - This build contains an Animated Preview Pane Aurora, but requires some modification to enable it.

Note: Only the x86 version has these features.


There are some bugs/issues present in this build, some of which are:

  • No Mouse Driver in WinPE - On some computers and emulators, the mouse does not work in the WinPE for this build and subsequent builds. If the mouse doesn't work, you must use the keyboard to navigate the WinPE.
  • Folder Creation Bug - The option to create folders by right-clicking and selecting New doesn't work as the Folder entry is hidden. However, several unofficial patches have been created to address this issue. Also, folder creation may be enabled by applying the following registry key:
Windows Registry Editor Version 5.00


  • Memory leak in explorer.exe - Turning off the sidebar remedies this issue.
  • Faulty File Browse UI - The main File Browse UI has two noticeable bugs. The first being that the Navigation Bar only allows for navigation by clicking on parent directories in the bar. The second being that the Filter and Preview panes may occasionally appear black or show parts of content behind the window.
  • Broken Safe Mode - This build has a glitch with the Explorer Safe Mode desktop prompt. The prompt will appear titled "Desktop" and will ask to proceed to work in safe mode or to System Recovery. Clicking either button will hardly perform any action and will bring up another exact prompt. The desktop will not appear with the prompt and Explorer may not launch. This makes any work in Safe Mode almost impossible. Using Safe Mode with Command Prompt will work as long the Explorer shell isn't loaded.