Windows Vista build 5048

Windows Vista build 5048 is the first pre-Beta 1 build of Windows Vista to leak after the development reset of Windows Longhorn. This build was released to attendants of WinHEC 2005, and was known as the "Longhorn Developer Preview". It calls itself Beta 1 in the setup handle, but it's not the true Beta 1.

Being a pre-beta 1 build, it is noticeably closer to Windows XP and Windows Server 2003 than to pre-reset builds. It is also an idx02 build, which suggest 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, it was compiled in evaluation mode, and it can be installed on the current date. The timebomb in evaluation mode behaves just like pre-reset builds; if the timebomb expires, the user is automatically logged out.

Setup
Although previous builds of Vista re-used the older i386 installation process, this build re-uses the Windows Preinstallation Environment installation process from later builds of Longhorn, retaining the slate theme as well. However, a few changes have been made. The launching WinPE screen does not show anymore, now leaving you without any option of pressing F6 to load in certain drivers. The starting setup screen has also been majorly uplifted, now containing the windows flag. Anti-aliasing is no longer present on fonts, and the numbers on the progress bar no longer glow. Finally, the hardware portion of setup now includes a dummy progress bar on the bottom (all it does is just continuously increase in size until it reaches the end, then it goes back to the start), and the Windows flag has been added to the middle of the page. Asides from all of these minor changes, setup is overall mostly similar to what was found in later pre-reset builds of Longhorn.

New features and changes

 * This build includes Windows System Assessment Tool (shortly WinSAT) and Windows Diagnostic Infrastructure (WDI).
 * The Jade and Slate themes are no longer included.
 * Windows Media Player 10 and Internet Explorer 6 SP2 are also now present.
 * Sync Manager (Later known as Sync Center) has been introduced.
 * Many of the icons from later pre-reset builds have returned, albeit with minor alterations. A few icons are also new to this build. However, the Control Panel and Printers icons are from Windows 95.
 * This build uses the old way of logging in (the one seen in Windows 2000) by default. The 'new' login screen can be enabled in the control panel, but it is just an exact replica of Windows XP's login screen.
 * This build uses  as the default bootloader, but still includes   as an alternative way to boot. This can be seen via a dual boot. As a result, this build also contains the notable red screen (RSOD) when a boot error occurs. This build is the first to not boot without ACPI, since it results in an error.
 * You can choose a bunch of different themes, including the Windows XP Luna themes, the classic theme, and the three new Aero themes.
 * Paint received an update which added a zoom slider to the app (it was readded from Windows Longhorn build 4051).
 * Self-Healing NTFS was reintegrated from Windows Longhorn build 4074.
 * Instant Search was implemented in this build.
 * Control Panel's Category View was revamped and applets were added for installed programs.
 * Search UI was updated to manage search criteria specifications.
 * Microsoft Anna Speech Synthesizer from build 4093 was added. However, it is slightly different.
 * Search UI was updated to manage search criteria specifications.
 * Microsoft Anna Speech Synthesizer from build 4093 was added. However, it is slightly different.

Start Menu

 * Start Menu received many new updates in this build including the famous search box that will later be seen in Windows Vista and Windows 7, and the outlining of the start menu being transparent.
 * "All Programs" menu is now an inline menu and it doesn't open in a separate context menu-like UI.
 * Customize Start Menu has references to "My Games" and "My Hardware" links.

Aero

 * This build makes the debut of the Aero theme, by default it is loaded without DWM.
 * This build includes three new Aero themes.
 * One of the new Aero themes (Theme 2) use a similar design to later builds of Vista (The only difference is that the minimize and maximize buttons are little arrows, minimize arrow points down and maximize arrow points up, but other than that, its basically the same.)
 * Aero theme is now the default theme overall system, along with its visual effects and wizards.

Desktop Window Manager
This build of Vista readds the Desktop Window Manager, after being absent in builds 4083-4093 (including Omega-13 builds 3790, 5000 (with multiple compiles) and 5001). This build includes Desktop Window Manager, but it can crash at startup if no driver is installed, in which case software emulation is needed if no driver is available. LDDM drivers are now included by default, supporting many (but not all) GPUs of the time, however the DWM can run with a regular XPDM driver, using a registry edit.

There are two different ways of initializing DWM, one by modifying the registry, while the other being initializing a DLL via rundll32.exe. The more simpler rundll32.exe method is simply opening up the command prompt, and typing. This, however, randomizes the effects used with DWM. 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 3 DWORDs inside the key: Once making the following changes, simply log out of the system, then log back in.

User Account Control

 * This build includes User Account Control (A prototype version of this feature can be first seen in Windows Longhorn build 4031)

Bugs and quirks

 * 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.
 * There is a limit of 50 files able to be browsed per folder, but it can be bypassed by viewing icons in groups.
 * 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.
 * Help and Support does not open due to a missing, but an updated help application, called  , can be found in the Windows folder.
 * 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.