Windows Vista build 5048

Windows "Longhorn" 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.

New features and changes

 * The Jade and Slate themes are no longer included, and the Aero theme is now the default, along with its visual effects. This build also has a new wallpaper and some Vista-like interface areas.
 * Windows Media Player 10 and Internet Explorer 6 SP2 are also now present.
 * The Start menu has been revamped, and also contains a search feature. This feature would later make it onto the RTM of Windows Vista and on later versions of Windows.
 * 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 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.
 * 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 3 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.)

Bugs and quirks

 * Reportedly, there is a limit of 50 files per folder imposed, 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.
 * You must make a new drive partition before you install this build.
 * A 0x7b BSOD may occur after the first reboot.