Windows Vista build 5048

Windows "Longhorn" build 5048 (with a build tag of 5048.winmain idx02.050401-0536) is the first Omega-13 build of Windows Vista to leak after the development reset of Windows Longhorn. It 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 is not the true Beta 1.

The Jade and Slate themes are no longer included, and the Aero theme is now the default, along with its visual effects. It has a new wallpaper and some very Vista-like interface areas. Windows Media Player 10 and Internet Explorer 6 SP2 are also now present. 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. The x64 edition of this build is similar to the x86 build, but it has a different EULA and Windows XP x64 Edition brand wallpaper instead of Windows Code Name Longhorn brand wallpaper which is named as winxp.jpg.

Being an Omega-13 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.

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 also uses, 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 when a boot error occurs. This build is the first to not boot without ACPI, since it results in an error.

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 will make the login screen throw up an error. This can be safely ignored.