Windows Vista build 5048

Windows Vista build 5048 is a pre-Beta 1 build of Windows Vista. It is the official Longhorn Developer Preview, which was released to attendants of WinHEC 2005 on 24 April 2005. The checked/debug versions of this build were uploaded on 26 December 2021 by ReflectiaX.

Being a pre-beta 1 build, it is noticeably similar to Windows XP and Windows Server 2003 than to pre-reset builds. It is also an  build, which suggests that it was recompiled several times, and therefore is behind regular builds compiled at the time. The x64 version of this build is similar to the x86 build, but it has a different EULA and Windows XP x64 Edition brand wallpaper instead of the Windows Server 2003 brand wallpaper which is named as.

Unlike other post-reset Vista builds, this build was compiled under evaluation mode and can be installed on the current date. The timebomb in evaluation mode behaves identically to pre-reset builds; if the timebomb expires, the user is automatically logged out.

This is the latest available Windows build to include the Luna theme. It is also the last known build of Windows to include the game 3D Pinball Space Cadet, as well as the last to include the login prompt used in Windows 2000 build 1946 and onward, and the logoff prompt used in Windows 2000 build 2031 and onward.

Setup
Although previous builds of post-reset Vista used the older i386 installation process, this build reimplements the Windows Preinstallation Environment installation process from later builds of Longhorn, retaining the older Slate design as well. However, a few changes have been made. The launching WinPE screen does not show anymore, now leaving the user without any option of pressing F6 to load in certain drivers during boot. However, the user still can load drivers by selecting the "Load Driver" option at the page where the user decides where Windows will be installed, signified by an F6 key icon.

The starting setup screen has also been altered, and now features the Windows flag. The ClearType functionality originally seen in most pre-reset builds' Preinstallation Environments has been disabled, and the step numbers on the progress bar no longer glow. The hardware portion of setup now also includes a dummy progress bar at the bottom of the screen that repeatedly fills itself up, and the Windows flag has been added to the middle of the page. A minimum hardware limit of 256 MB of RAM has also been imposed in an effort to reduce the chances of installation failure. Aside from all of these minor changes, setup is overall mostly similar to what was found in later pre-reset builds of Longhorn. Unlike other Longhorn builds, however, the Windows Classic visual style is present in a similar fashion to build 4093 and builds 7955 to 7978 of Windows 8.

New features and changes
A majority of features that were added in this build were the result of feature backporting from builds compiled prior to the development reset.
 * This build includes Windows System Assessment Tool (shortly WinSAT) and Windows Diagnostic Infrastructure (WDI). However, WinSAT is not functional and links lead to an intranet website instead.
 * Sync Manager (Later known as Sync Center) has been introduced.
 * Many of the icons from later pre-reset builds have returned, some with minor alterations. A few icons are also new to this build. However, the Control Panel and Printers icons are from Windows 95, just like late pre-reset builds.
 * This build uses the legacy login dialog in place of the regular Windows XP login screen. The aforementioned login screen can be enabled through the User Accounts Control Panel applet, and is a leftover that would be removed before build 5098.
 * A zoom slider has been added to Paint.
 * Self-Healing NTFS was reintegrated from pre-reset build 4074.
 * Instant Search was implemented in this build.
 * The Control Panel was revamped, bearing a similar design that is comparable to the RTM build.
 * The Microsoft Anna speech synthesizer, first seen in pre-reset build 4093, was reintroduced.
 * ClearType is now enabled again after being disabled since Windows Longhorn build 4081.
 * This build changes the  screen color to blue and the text color to black.

Windows Boot Manager
This is the first known build to include the Windows Boot Manager, which replaces  as the default bootloader since its introduction in the Windows NT 3.1 October 1991 build. However,  is still included as an alternative way to boot and can be observed if dual-booted with an earlier version of Windows. Additionally, this build still uses  instead of BCD.

Unlike later builds, the error screen is red, leading to it being called a red screen of death. Furthermore, the advanced boot options screen is blue. Text mode is also used at all times, while later versions use a framebuffer console in a VESA-compatible mode if possible.

This is also the first build to require ACPI support, as it is required by the new boot loader and trying to start Windows on a non-compliant system results in an error.

Windows Explorer

 * My Computer has been renamed to Computer, as with late pre-reset builds.
 * File checkboxes and scalable icons, first seen in pre-reset builds, have been reintroduced.

Setup
Starting with this build, an upgrade from Windows NT 4.0, Windows 98, Windows 98 SE and Windows Me is no longer supported.

Start menu
The start menu received a number of updates, which include (but are not limited to) a search box, transparency and an inline menu replacing the original All Programs context menu.

Desktop Window Manager
This build of Vista reintroduces the Desktop Window Manager, which was originally absent since the development reset. The window manager will crash on startup if no GPU driver is installed, and software rendering is required if no compatible driver is available. Although LDDM drivers are now included by default, which claim to feature support for most GPUs at the time of compilation, there has currently been no success in attempts focusing on enabling the driver stack (even with drivers that were ported from other builds), highlighting the possibility that the graphics stack may not be functional. However, this build's DWM subsystem can run with a regular XPDM driver as long as a whitelisted GPU is either installed or if the whitelist is bypassed through means of registry modification.

There are two different ways of initializing DWM, one is modifying the registry, while the other is initializing a DLL via. The more simpler rundll32.exe method is simply opening up the command prompt, and typing, this applies the DWORDs described below in the registry, or if none of the DWORDs exist then the effects will be randomized. The other method of initializing DWM can be done via opening the Registry Editor, navigating to, creating a new key called DWM, then creating the following DWORDs inside the key:

Next, run  set User Experience Session Management Service startup type to Automatic and enable it.

After making these changes, log out (and vice versa) to initialize DWM. The functionality can be toggled on and off using Ctrl like in most other builds featuring DWM, however that works only if User Experience Session Management Service is running.

Windows Aero

 * This build marks the debut of the Aero theme (which is loaded by default without DWM), and features two glass theme variants.
 * The alternate caption button incorporates a design similar to build 4050.
 * The Aero theme is now the default overall system theme, along with its visual effects and wizards.

User Account Control
This is the first build after the development reset to include a preliminary version of User Account Control.

Removed features

 * MSN Gaming Zone
 * Windows NetMeeting (which would be replaced with Windows Meeting Space later during development)
 * Windows XP Tour
 * Filmstrip view in Windows Explorer
 * Media Player 2 and Windows Media Player 6.4
 * 32-bit variant of Dr. Watson, though the 16-bit variant still remains in the x86 version.

Bugs and quirks

 * There is a limit of 50 files able to be browsed per folder, but it can be bypassed by viewing icons in groups.
 * The File Explorer will not refresh after changing settings.
 * On-Screen Keyboard will not launch due to the registry file being corrupt, and it will use a wrong icon.
 * Enabling auto login for the default user account while having the new login screen enabled can make the login screen throw up an error. This can be safely ignored.
 * The  option is missing from the new login screen.
 * With fast user switching enabled, the "Switch user" option doesn't appear when selecting "Log Off". Instead, the Log Off dialog is always the one Windows XP would display with fast user switching disabled. It is still possible to switch users using the key combination Windows+L.
 * Help and Support does not open due to a missing, but an updated help application, called  , can be found in the Windows folder.
 * The Windows logo has a white background on the hibernation screen.
 * The Luna theme is noticeably broken and uses Slate graphics for the right pane of the Start menu.
 * The Control Panel/Printers and Faxes icons are from Windows 95. The correct icon can be found in the resources.
 * The default set of buttons with the Aero theme is downscaled to a smaller size.

Installation

 * The setup switches to 16-bit color 800x600 video mode after briefly using 24-bit 640x480 during its startup, resulting in a noticeable dithering effect of the background during setup.
 * Although this build can partition properly during setup, the partitioning page doesn't refresh properly, requiring you to reboot your system in order to see the new partition.
 * The timer located at the bottom-right corner in setup is not functional, as it always displays  regardless of the progress.
 * The Checked/Debug version may cause a red screen crash after installation because the BCD is not created normally.

Upgrading
While this build requires build 5019 or higher to upgrade to,  in the sources folder lists various bugs that will be encountered when an upgrade takes place. preupgradenotice.txt 

File differences
The following files have been introduced, renamed or removed from build 5001: