Windows Longhorn build 4074

Windows Longhorn build 4074 is a Milestone 7 build of Windows Longhorn. This build is the official WinHEC 2004 preview build, released in 4 May 2004.

Setup
Setup overall is mostly similar to previous builds of Longhorn. The timebomb exists; but it won't activate, so this build can be installed on the current date without trouble.

Segoe UI
This is the first build to use the Segoe UI font as its default font, which was also found in later operating systems.

New icons

 * Many of the icons were replaced with new, more modern icons, such as the My Computer and Internet Explorer icons.
 * The user profile picture has been replaced with a gray variant.

"Jade" visual style and "Leaves" wallpaper
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, like in Windows Vista RTM).

Aero

 * This build, unlike many other leaked builds, is the first build to have complete Aero effects in Explorer and Internet Explorer from the Desktop Window Manager, thanks to an early version of MILExplorer. 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". Further modification (such as a modified version of the build such as TWIWMTB (Longhorn The Way It Was Meant To Be) or a patched  file) is required to replace the translucent borders with glass. See the Windows Aero page for instructions on how to enable Aero effects.
 * This build also contains Aero Stars, an animated desktop which shows stars bouncing around the screen. It is somewhat buggy, and some graphic adapters may have trouble rendering it.

Preview panes

 * This build has the preview and filter panes improved, especially the Preview Pane, which is more functional than its leaked server counterpart, build 4066.
 * This build contains an Animated Preview Pane Aurora, but requires some modification to enable it.

Buddy matchmaker
This is the earliest leaked build of Longhorn to include the buddy matchmaker.

Other new features and changes

 * MSN Messenger has been updated to version 6.1, with a completely new interface.
 * This build contains numerous updates to general prompts, ranging from the Autorun prompts to "not responding" dialogs.
 * A new driver installation system is implemented. As a result, most drivers that worked on Windows XP will often have the driver installation fallback to a "pre-release mechanism" upon installation. If you get a pop-up notifying about the pre-release mechanism, simply press cancel.
 * IIS has been updated, but in Windows Components Wizard it says IIS 7.0; after installation it claims to be version 6.5.
 * Libraries have been updated and now have a majorly uplifted banner.

Do note the features related to .NET Framework, such as the sidebar, full Aero or Aurora, don't work on the amd64 version. Basic DWM functionality is present, but can be enabled by directly calling relevant uxdesk.dll exports using rundll32 and a command prompt or extracting sbctl.exe from the installation media.

Installation

 * This build cannot be upgraded from a previous build, and can only be clean installed.
 * The Checked/Debug compile of the x64 version has an assertion error in the IDE driver that results in a BSOD during "Completing installation" phase with an error code of 0x1E and 0xFFFFFFFF80000003 as there were no kernel debugger attached at that point. When this occurs, start WinDbg on the host, connect the debugger to the VM's virtual serial port (shut down the VM then add and configure one if there are none in your VM), then restart the VM and press the F8 key to select "Debugging Mode" and continue the setup. Once the "Assertion failed" message appears, type "ignore" or the letter I to the debugger command window. Repeat this on every message until the setup finishes.

Timebomb
It is one of the notable Longhorn builds that has a broken timebomb and can be installed on the current date.

Themes
Upon changing themes, three are a few bugs you can encounter. One of which is the services theme can malfunction, causing the taskbar to have the classic theme visuals, and the start menu possibly being entirely black. This is generally easy to fix, however, since all it requires is restarting the Themes and Desktop Manager service in services.msc, or switch to the Windows Classic theme and then revert back to Windows XP Luna, Slate, or Jade themes. Another issue, which is more likely, is Explorer failing to render entirely. If possible, press the CTRL+ALT+DEL keys and open Task Manager to terminate explorer.exe, otherwise you're only left with restarting the system.

The Aero theme works with most of the existing visual styles, causing visual glitches especially when using the Classic theme, in which crashes the Explorer itself.

Wallpaper bug
Sometimes, when choosing a wallpaper, the desktop may glitch out.

Aero
Sometimes, the Aero Explorer may display the text overlapped. TWIWMTB Aero theme is rendered incorrectly, leaving the bottom part without a frame.

This theme is incorrectly scaled when using a Windows Classic color scheme with large fonts and Aero.

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. This seems to be related to using a PS/2 mouse, as USB mice seems to work fine for the setup.

Creating folders
The option to create folders by right-clicking and selecting New doesn't work as the Folder entry is missing. Apply the following registry key to fix this problem:

Memory leak
As with most later Longhorn builds, this build's Explorer tends to leak memory after a while. Turning off the Sidebar reduces the effect of the memory leak.

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.

Buddy matchmaker
Unlike build 4093, the buddy matchmaker application throws out errors.

Safe mode
If Sidebar is enabled in Safe Mode, it will cause Windows Explorer to crash in a loop. A prompt will appear titled "Desktop" and will ask to proceed to work in safe mode or start System Restore. Clicking either button will not perform any action and will bring up another exact prompt instead. The desktop will not appear with the prompt and Explorer may not launch unless you turn off Sidebar:

Additionally, when Windows Explorer is running in Safe Mode, clicking on Log Off from the start menu or initializing the Shut Down dialog box via Alt + F4 on the desktop with Safe Mode, it will bring up another exact prompt. So to log off, shut down, or restart, press the CTRL+ALT+DEL key and then click on "Log Off", "Shut Down", or the ">" button for more options.
 * 1) Start in Safe Mode with Command Prompt.
 * 2) Type in   in the Command Prompt window.
 * 3) Navigate to.
 * 4) Create a DWORD (32-bit value), name it Enabled, set it to 0, and then close Registry Editor.
 * 5) Type in   in the Command Prompt window, once done, Windows Explorer will now start in Safe Mode.

Itanium build specifics
Similar in manner to its feature set, the IA64 compile also contains all of the bugs and quirks the x86 compile has. However, there are some notable exceptions:
 * Because the IA64 build lacks WinFS, Outlook Express, along with WinFS provided virtual folders/libraries do not function.
 * Due to the "heavier" nature of 64-bit binaries, Explorer will consume at least 150 megabytes of memory even without advanced features (such as the sidebar) enabled, right after logging in.
 * Certain graphics driver versions will cause lag and hanging when .NET features (such as the sidebar) are enabled. It is best to turn these features off when trying driver versions.
 * Pressing Ctrl + Alt + Del at the login prompt (when it is required/enabled) has a chance to either hang the system or cause a PAGE_FAULT_IN_NONPAGED_AREA crash. This chance increases the more users have logged on and off.
 * Explorer works properly in Safe Mode. Clicking Yes on the Safe Mode information dialog dismisses it and Explorer starts normally.
 * If upgraded from a previous IA64 build, the registry will not be configured correctly. It is best to perform a clean install. If installing over a previous build, the hard disk must be completely wiped and the system's EFI firmware cleared of previously created Windows boot entries or the build will not boot due to an NVRAM related error. Entries and dual-boot installations on separate partitions created by later, RTM operating system builds (such as Windows Server 2008) may be left alone.
 * Explorer may also randomly crash when opening folders with a "Fatal Execution Engine Error."
 * Opening DirectX Diagnostics (or using any DirectX-related feature including the Autorun prompt) after changing display resolution will hang the system. It is best to restart immediately after changing the display resolution.

Aero themes
This build of Windows Longhorn includes 4 types of Aero themes, in which 2 of them are patched. The default Aero theme (seen in the first image in this section) is opaque.