Windows Vista/6.0.5048.winmain idx02.050401-0536

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".

Build 5048 includes a number of design concepts and features that would be present in the RTM version of Windows Vista including the Windows AERO theme and visual effects, a search box in Windows Explorer, a new Category organizational structure for the Control Panel, and the Sync Manager. It is the also the first known build to include an instant search feature on the Start menu—a feature previously present in "Longhorn" concepts—and it also introduces a treeview for the "All Programs" view on the Start menu. Pre-reset "Longhorn" interface features include the breadcrumb bar, command bar, and the details pane; capacity indicators for free disk space in Computer; the Edit Property context menu option in the Windows Shell for metadata properties; and visible column headers in all icon viewing modes.

This build also includes preliminary features that were prominent within the pre-reset "Longhorn" interface, though they do not work by default: The "Show Picture Preview on Hover" feature for pictures in Windows Explorer, and a reference to Ink File Names—a feature previously shown during PDC 2003 and discussed during WinHEC 2004. Checkboxes (previously seen in pre-reset "Longhorn" Build 4051) are also included for Windows Explorer, but are not enabled by default.

Although Microsoft had made a significant amount of progress in reinstating "Longhorn" features, many were surprised that this and similar builds more closely resembled Windows XP and Windows Server 2003. Technology blogger and Windows enthusiast Paul Thurrott once notably stated: "'My thoughts are not positive, not positive at all. This is a painful build to have to deal with after a year of waiting, a step back in some ways. I hope Microsoft has surprises up their sleeves. This has the makings of a train wreck.'"

This build includes the Desktop Window Manager (DWM), but it is unstable; BetaArchive user ovctvct wrote a tutorial on how to enable DWM without any crash.

Features
Build 5048 includes preliminary versions of core features that would appear in the RTM version. As Build 5048 is the first build to be released publicly by Microsoft after the development reset, it is notable and significant for being the first post-reset build to incorporate many of the concepts and features that were seen previously.

Some of its features include:
 * A new Category viewing mode for Control Panel and applets for installed programs
 * A new zoom feature in Microsoft Paint (previously observed in Windows "Longhorn" Build 4051)
 * AERO Wizards
 * Advanced Search UI for specifying search criteria
 * AutoLists
 * Desktop Window Manager
 * Edit Property context menu option for metadata properties in the Windows Shell (previously observed in "Longhorn" Build 4074)
 * Help and Support Center (Help Pane)
 * Improvements to Windows Explorer
 * Addition of the breadcrumb bar, the Command Bar, the reinstatement of the Details Pane
 * Capacity indicators for partitions in Computer
 * Checkboxes for files
 * Visible column headers for all icon viewing modes, with new options for grouping and sorting files
 * Ink File Names option
 * Instant Search
 * Lists (Static Lists)
 * "Longhorn" Error Reporting
 * Microsoft Anna speech synthesizer
 * Network Access Protection
 * Network Location Awareness (NLA)
 * People Near Me
 * Portable Media Devices Control Panel applet seen in "Longhorn" 4074
 * Scalable icons (activated by holding the CTRL key and moving the mouse scroll wheel)
 * Self-Healing NTFS (previously observed in Windows "Longhorn" Build 4074)
 * Speech recognition; speech training wizard
 * Start menu features, including a search box and inline "All Programs" menu
 * Sync Manager
 * User Account Control
 * Windows Diagnostic Infrastructure (WDI)
 * Windows System Assessment Tool (WinSAT)
 * No longer works without ACPI.

AutoLists and Stacks
"Longhorn" 5048 introduces the AutoList feature, which aggregates and displays content based on a query instead of a hierarchical folder structure. AutoLists for documents, music, and pictures are included and are nested within their corresponding traditional folders (e.g., All Documents is stored in Documents) and featured within the navigation pane of Windows Explorer. AutoLists in this build include: Many of the principle AutoLists in this build—namely, All Documents, Authors, Keywords, Recent Documents, Album Artists, Albums, Favorite Music, Genre, Music, and Ratings—would become pillars of Microsoft's vision for this feature with the release of Virtual Folders in later post-reset builds of Windows Vista. With the introduction of AutoLists in this build, the following pre-reset "Longhorn" query examples are now possible in Windows: "All recently created Word documents", "All Pictures taken in 2003 of Joe", and "All Rock Music that I've rated 5 stars".
 * Documents: All Documents, Authors, Keywords, Recent Documents, Types
 * Music: Album Artists, Albums, Favorite Albums, Favorite Music, Genre, Music, Ratings
 * Pictures: Events, Locations, People, Photos

For photos, the Events, Locations, and People AutoLists were removed from post-reset builds as of Windows Vista Build 5112. The Event metadata property, however, is supported in Windows Vista RTM. For music, the Favorite Albums AutoList is similar to the Albums Autolist—the only difference is that the former presents icons at a size of 13px instead of 16px; it does not actually aggregate or display albums or even music tracks that have been rated.

This build notably also includes the Metadata Painting feature that Microsoft discussed during PDC 2003, which allows one to drag an item into a stack—a collection of items assembled by a metadata property—to write the referenced metadata property to that item. Dragging a document without an assigned author into an Author A stack in this build, for instance, will assign Author A as the author of that document. Items can also be grouped by a metadata property, and dragging and dropping an ungrouped item—or an item from within one group to another group—will write the referenced metadata property to that item (this feature is also present in pre-reset "Longhorn" Build 4074).

Static Lists
Static Lists (of pre-reset "Longhorn"), which allow the user to create a list of items—independent of location—that are assembled in a definite order and (optionally) annotated with comments are notably included in the post-reset Build 5048. Examples of their use include audio playlists, client presentations, files to share, photo albums, research projects, and shopping lists. Static Lists can be sent as attachments in email—instead of the sharer sending copies of the referenced items—or over a network and the most recent versions of annotations and items will always be available to the sharee for viewing.

The static adjective qualifies that items are explicitly collected and arranged by the user. In contrast, AutoLists aggregate and display items based on a query (e.g., all music tracks by a specific artist) and update dynamically when new items that meet the defined query criteria are discovered.

As implemented in Build 5048, a Static List is an XML file (based on the Synchronized Multimedia Integration Language (SMIL) for Windows Media Player playlists) that references items; references in a Static List are not copies or shortcuts to underlying items. The XML file implementation relies on a conventional file system and the serialization of shell link data (e.g., when an item was created) to automatically identify and update references; it is prominent in pre-reset builds and is included in 4051, 4074, 4093; however, 4093 partially relies on "WinFS" for Static Lists, particularly for those dedicated to the staging and burning process for optical media.

The primary differences between an XML file-based implementation and a database implementation (e.g., "WinFS") are interoperability—with a conventional file system, the former is readily accessible—and the ability to remove references to underlying items deleted since their creation; the database approach is preferable (but not necessary) in the latter scenario. In pre-reset builds and Build 5048, deleting underlying items does not remove their references from Static Lists.

Static Lists are included up to Build 5212 (where they are updated to use RSS Simple List Extensions).