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". This build cannot be upgraded from an earlier build, just be installed as a clean install.

The Jade and Slate themes are no longer included, and the Aero theme is now the default. 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.

This build features the Windows Aero theme and visual effects. Reportedly, there is a limit of 50 files per folder imposed, but it can be bypassed by viewing icons in groups.

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 DWM, 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. It calls itself Beta 1 in the setup handle but is not true Beta 1.

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. The auto login used for the default user account in the build makes the new login screen throw up an error. This can be safely ignored.

This build also uses BootMGR, but still includes NTLDR as an alternative way to boot. This can be seen via a dual boot. This build is the first to not boot without ACPI, since it results in an error.

x64 version
The 64-bit edition of this build is similar to the x86 build, but it has a different EULA.