Windows Vista build 5048

Build of Windows Vista
Release nameLonghorn Developer Preview
OS familyWindows NT
Version number6.0
Build number5048
Build revision0
Architecturex86, x64, IA-64[a]
Build labwinmain_idx02
Compiled on2005-04-01
Expiration date
Timebomb+180 days after original install date
Enterprise Server (Foundation)[b]
Product key
About dialog
TCB.png TCBGallery.png

Windows Vista build 5048 is the official Longhorn Developer Preview build of Windows Vista, given to attendees of Microsoft's Windows Hardware Engineering Conference 2005 on 25 April 2005[1] in Seattle, Washington, held between 25 and 27 April. The checked/debug versions of this build were uploaded by ReflectiaX on 26 December 2021.

As an early post-reset build, it is noticeably more similar to Windows XP and Windows Server 2003 than to pre-reset builds. It is also an idx02 build, which suggests that it was recompiled several times, and therefore is behind regular mainline builds. The x64 compile of this build is similar to the x86 variant, but features a different end-user license agreement and alternative 64-bit branding resources.

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.

New features and changes[edit | edit source]

A majority of features that were added in this build were the result of feature backporting from builds compiled prior to the development reset.

Windows Setup[edit | edit source]

Although previous builds of post-reset Vista used the older setup process featured in previous releases of Windows, this build reimplements the newer WIM-based image deployment process from pre-reset Longhorn builds, albeit with several functionality changes.

The design of the setup initialization screen has been altered to include the Windows flag. The ClearType functionality originally seen in most pre-reset builds has been disabled in the Preinstallation Environment, and stages presented under the initial progress indicator no longer bear a glow effect. The ability to load disk drivers has been moved over to the disk partitioning stage, and a progress bar that reports fake percentage information is now shown when Windows is assembling the image and detecting hardware during the second stage of setup.

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 these minor changes, setup is largely similar to what was found in later pre-reset builds of Longhorn. Upgrades from Windows NT 4.0, Windows 98 (including the Second Edition re-release) and Windows Me are no longer supported.

User interface[edit | edit source]

The user interface has seen a gradual overhaul over previous builds; although parts of the interface are largely similar to its predecessor, a number of changes can be observed across various surfaces. The Windows Aero visual style, which sports a design featuring shiny metallic and glass surfaces, has been added to the operating system; it is the default system theme throughout the rest of Vista development and would act as a complete replacement for the legacy Luna visual style, initially present as a development placeholder in builds up to 5059 (vbl_wcp_avalon). ClearType anti-aliasing is now enabled across all surfaces by default.

The Windows Explorer application design has been updated to feature a design that largely resembles the one introduced in pre-reset build 4042 (Lab06_n) (additionally coupled with a search box prefixed at the top-right), and a near-final layout design for the Control Panel has been introduced along with a classic category view. Several icon designs from earlier pre-reset builds have been reintroduced with slight alterations, along with the introduction of several new icon designs for features such as networking, Paint, Help and Support and several Control Panel applets including Program Defaults and Printers and Faxes. Shell folders such as the Documents and Computer folders have had the "My" prefix dropped from their names. The start menu received slight design changes, which include a built-in search utility and an inline menu replacing the original All Programs context menu.

A basic implementation of the Search Indexer (disabled by default) was implemented along with a full overhaul of the older search user interface. Virtual search folders that automatically categorize files based on existing metadata, otherwise referred to as "AutoLists", have also been implemented into the existing set of built-in user account folders. The ability to manually select files through the use of check boxes and scalable file icons via mouse wheel scroll have also been implemented. The Filmstrip folder view, which included a basic image viewer, was removed in favor of larger icon-based previews.

The Sync Manager feature was implemented, allowing users to set up one or more devices with a server allowing for basic file management over a network. It can be manually invoked by running the mobsync.exe application, accessing the "Synchronize" option from the Windows Explorer's "Tools" drop-down menu or by opening its respective Control Panel applet.

The legacy login dialog from Windows 2000 is used by default in place of the regular Windows XP login screen; the newer design (which has less functionality compared to the one found in Windows XP) can be enabled through the User Accounts Control Panel applet. Both designs act as development placeholders that would be removed the lead-up to Beta 1. Legacy versions of the Windows Media Player applications have been removed, along with the built-in MSN Internet Games, the Windows XP Tour and Windows NetMeeting (later succeeded by Windows Meeting Space).

Desktop Window Manager[edit | edit source]

This build of Vista reintroduces the Desktop Window Manager, a 3D windowing compositor functionality that 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 display driver is available. Although LDDM-compatible 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 ported from other builds), highlighting the possibility that the graphics stack may not be functional. This build's DWM subsystem can be run under a regular display driver intended for Windows XP or Windows Server 2003 (classified under the XPDM model), so long as a whitelisted GPU is either installed or if the whitelist is bypassed through means of a development-specific override.

There exist two different ways of initializing DWM: either by adding a hardware check override into the registry or by invoking function DwmClientStartup in library uDWM.dll. The first method can be achieved by opening the Registry Editor, navigating to HKEY_LOCAL_MACHINE\Software\Microsoft, creating a new key called DWM and creating the following DWORDs inside the key:

Key Values
EnableMachineCheck 1 - enables the graphics hardware check, which restricts DWM support to the ATI Radeon 9800 and NVIDIA GeForce FX 5900 series[c]

0 - disables graphics hardware check

ForceSoftwareD3D 1 - forces software rendering

0 - hardware rendering



1 - makes window frame designs yield an opaque Jade-like style, similar to the one observed in pre-reset builds

0 - glass window frames observed in pre-reset build 4050



1 - square-like buttons

any other value - build 4050's Glass buttons



0 or 100 (decimal) - normal horizontal scaling

any decimal value in range of 1 to 99 - horizontal downscaling percentage of windows

any decimal value more than 100 - horizontal upscaling percentage of windows



0 or 100 (decimal) - normal vertical scaling

any decimal value in range of 1 to 99 - vertical downscaling percentage of windows

any decimal value more than 100 - vertical upscaling percentage of windows

After applying the aforementioned changes, enable the User Experience Session Management Service (uxsms) by setting its startup type to Automatic, and then log out (and vice versa) to initialize the Desktop Window Manager. Composition can be toggled between on/off states by using the Ctrl+⇧ Shift+F9 hotkey much like most builds featuring DWM, although it only functions if the service is running.

Windows Boot Manager[edit | edit source]

This is the earliest available build to include the Windows Boot Manager (BOOTMGR), which replaces NTLDR as the default boot loader since its introduction in the Windows NT 3.1 October 1991 build. However, NTLDR is still included as an alternative way to boot and can be observed if dual-booted with an earlier version of Windows. The older BOOT.INI entry format is still utilized as the registry hive-based Boot Configuration Data format was not yet implemented by Beta 1.

Advanced Configuration and Power Interface (ACPI) support is now required in order to boot into the operating system. Attempting to boot Windows under a non-ACPI-compliant system will yield a message advising the user to either upgrade their machine or contact their hardware manufacturer for support.

User Account Control[edit | edit source]

This is the first build after the development reset to include a preliminary version of User Account Control. It can be enabled by setting these values in the registry:


After this, give the administrator account a password, create a limited user account and log in to it.

Miscellaneous[edit | edit source]

  • The Microsoft Anna speech synthesizer, first seen in pre-reset build 4093, was reintroduced.
  • Branding in verbose boot mode (enabled via the /SOS boot switch) has been updated.

Bugs and quirks[edit | edit source]

Interface[edit | edit source]

  • Windows Explorer may sometimes only display the first 50 files and folders in a directory.
  • User interface elements in Explorer windows do not update themselves properly when modifying folder options.
  • The On-Screen Keyboard application does not read the local user's configuration correctly and will refuse to launch.
  • Enabling auto login for the default user account while having the new login screen enabled may result in an error being thrown; this can be safely ignored.
  • The ability to switch users is not displayed even if fast user switching is enabled. It is still possible to switch to another user by using the ⊞ Win+L hotkey.
  • The Help and Support start menu item points to a missing helpctr.exe binary as it was removed in favor of an updated design internally named HelpPane.exe, located at the root of the Windows folder.
  • The Control Panel and Printers and Faxes icons utilize their 16-color icon variants sourced from Windows 95.
  • User Account Control (when enabled) may prompt for administrator privileges for initial setup actions multiple times on first logon.

Setup[edit | edit source]

  • The Preinstallation Environment switches to 16-bit color 800×600 video mode after briefly using 24-bit 640×480 on startup.
  • Although this build can partition properly during setup, a reboot is required in order to install onto any newly created partitions as the disk list does not update itself properly.
  • The timer located at the bottom-right corner in setup is a placeholder and will not dynamically update.
  • Setup may not properly generate the correct boot configuration data after the operating system image is decompressed onto the hard drive.

Upgrade issues[edit | edit source]

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


Longhorn ReadMe File for Internal Upgrades
Quality Statement
Build to build CBB upgrades complete OS migration successfully without data loss or a reinstallation of the OS, and a functional migration of the following items:
1.  Applications
·  Office 2003
·  Product Studio
2.  Developers’ Environment
·  Razzle Environment
·  Visual Studio 2005 Beta 1
·  Visual Studio 2003
3.  System Settings
·  Domain Membership, Security accounts with password, Computer Name
Measurement is based on a minimum of 100 systems installs (50 Lab and 50 Self Host system upgrade completions) and meeting the Longhorn Quality Gates.  For more detail on the release criteria, see http://winweb/warteam/_content.asp?id=46&r=905

** Restricted upgrade scenarios **

Upgrade is *NOT* supported in the following scenarios for this RI:

1.  OS being upgraded is a build lower than 5019 *
2.  OS being upgraded is an INF build (only CBB -> CBB upgrades are supported) *
3.  OS being upgraded is newer than the one being installed
4.  OS being upgraded is 64-bit, setup being run is x86
5.  OS being upgraded is a server build
6.  OS being upgraded is LH Home, setup being run is LH Pro
7.  OS being upgraded has multiple OS’s installed on the target partition

* Upgrade support is planned for these scenarios in future milestones.

** Known Migration Issues **

Some system settings don’t migrate

For this RI, system settings are not expected to migrate correctly yet – this is by design.  Known issues include the failure to migrate:
·  Mapped network drives
·  IE pop-up blocker – allowed sites
·  IE toolbars
·  Proxy server info
·  Printers & faxes
·  Folder attributes (sharing, compression, redirection, etc.)
·  Some desktop shortcuts

System setting migration will be supported by Beta 1.

**  Drivers do not migrate **

Some drivers (e.g. out-of-box video drivers) do not migrate.  You’ll need to reinstall drivers for now.  Going forward, more robust driver migration will be supported.  (Bug 1061700)

**  Upgrading a laptop results in loss of network connectivity. **

Temporary workaround is to use a wired connection and rejoin the domain.  (Bug 1062094)

**  Product Activation (WPA) timer is not reset on migration **

If Windows is not activated prior to migration, the 15-day activation timer continues to count down post-migration from the date of the last clean install.  The simple workaround is to activate Windows.  (Bug 1062178)

**  Fonts installed by applications are not installed to the system.  **

Temporary workaround is to retrieve the font from the Quarantine folder.  (Bug 1060342)

**  Outlook shortcut icon is not displayed in Start menu after migration; icon used doesn’t launch Outlook. **

Shell settings are slated to be migrated properly in the last RI prior to Beta 1.  (Bug 1059072) 

**  The home page of the .Net framework documentation becomes **

This is an IE setting, also slated for migration in the last RI prior to Beta 1.  Workaround is to repair the .Net framework install.  (Bug 1056495)

**  Visual Studio .NET 2003 Command Prompt -- one of the .NET tools is not migrated on the target machine. **

Command prompt still works fine – just the shortcut is missing.  Workaround = Start -> Run -> “cmd”.  (Bug 10565056)

Miscellaneous[edit | edit source]

  • The Windows logo bitmap stored within the kernel may not display itself properly when it is drawn by boot video driver function InbvBitBlt().

File differences[edit | edit source]

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

Added files
Name Description Version
wmstream.dll Windows Media Streamer DLL
wmvadvd.dll Windows Media Video 9 Decoder
wmvadve.dll Windows Media Video 9 Decoder
WMVDECOD.DLL Windows Media Video Decoder
WMVENCOD.DLL Windows Media Video 9 Encoder
WMVSDECD.DLL Windows Media Screen Decoder
WMVSENCD.DLL Windows Media Screen Encoder
WMVXENCD.DLL Windows Media Video Encoder
wpdconns.dll WPD Connection Objects 5.2.3790.3658
wpdmtp.dll 5.2.3790.3658
wpdmtpdr.dll 5.2.3790.3658
wpdmtpus.dll Usbscan transport layer for MTP driver 5.2.3790.3658
wpdtrace.dll WPD Tracing 5.2.3790.3658
wscmisetup.dll Installers for Winsock Transport and Name Space Providers 6.0.5048.0
WSDApi.dll Web Services for Devices API DLL 6.0.5048.0
wshBth.dll Windows Sockets Helper DLL
wshirda.dll Windows Sockets Helper DLL 6.0.5048.0
WUDFCoinstaller.dll Windows Driver Foundation - User-mode Platform Device Co-Installer 6.0.5048.0
WUDFHost.exe Windows Driver Foundation - User-mode Driver Framework Host Process 6.0.5048.0
WUDFPlatform.dll Windows Driver Foundation - User-mode Platform Library 6.0.5048.0
WUDFSvc.dll Windows Driver Foundation - User-mode Driver Framework Services 6.0.5048.0
wups2.dll Windows Update client proxy stub 2
xmlrw.dll Microsoft XML Slim Library 2.00.3526.0
Renamed files
Old filename New filename Old description New description Version
Moon flower.jpg Moon.jpg
Purple flower.jpg PurpleF.jpg
Red moon desert.jpg RedMoon.jpg
Stonehenge.jpg StoneH.jpg
Vortec space.jpg Vortec.jpg
Windows XP.jpg winxp.jpg
Removed files
Name Description Version
wmvdmod.dll Windows Media Video Decoder
wmvdmoe2.dll Windows Media Video Encoder
wowfax.dll Windows 3.1 Compatible Fax Driver DLL
wshatm.dll Windows Sockets Helper DLL 6.0.5001.0
wshisn.dll NWLINK2 Socket Helper DLL 6.0.5001.0

Gallery[edit | edit source]

Windows Setup[edit | edit source]

Interface[edit | edit source]

Windows Boot Manager[edit | edit source]

User Account Control[edit | edit source]

Control Panel[edit | edit source]

Themes[edit | edit source]

Media[edit | edit source]

Notes[edit | edit source]

  1. Debug symbols only.
  2. Present in component store. No known way of assembling this edition is available yet.
  3. Only the EnableMachineCheck DWORD value is required in order to enable Desktop Window Manager composition. The requirement can also be bypassed if substrings 5900 or 9800 are present in the GPU's device driver name.

References[edit | edit source]

  1. Thurrott, Paul. WinHEC 2005 Longhorn Developer Preview, Windows IT Pro. 25 April 2005. Archived from the original on 27 April 2005.