Windows Longhorn build 4005

Windows Longhorn build 4005 is a Milestone 4 build of Windows Longhorn. On 23 January 2020, this build was listed on a thread by UX.Unleaked blog founder Grabberslasher to be released to BetaArchive's FTP server, and was released in the second set of his 33 Longhorn/Vista builds on 25 January 2020, alongside build 4039 (Lab06_n.030824-1954) and the Home Edition of build 3790.1232.

It is a major update from previous builds such as build 4001, including an updated image-based installation process. It uses the new branding in  but still retains the Windows XP boot screen.

It is also the last build to use centered title bars for normal windows, which were later reintroduced in Windows 8 build 7779. Centered title bars for maximized windows would remain until build 4015.

Setup
In a similar fashion to 4001, the Setup interface received a design overhaul, and now features a less primitive user interface. This build makes use of the WIM-based installation method unlike the previous one.

Unlike 4001, characters used for product key input are no longer capitalized, although the ability to split parts of the product key with dashes is not yet present. The EULA page no longer requires the user to scroll to the bottom of the page in order to proceed and instead features two radio buttons for agreement. Drive partitioning has been improved and now features details of each disk with their associated partitions, rather than listing partitions only. The file copy phase now includes a simple, concise explanation on what Setup is doing.

During the second restart, a mostly empty page that asks the user to simply wait for an unspecified period of time is presented to the user. At this point, Setup will automatically detect installed hardware and attempt to finalize the install; this phase is most commonly referred to as the "hardware portion". The user will then be greeted with the out-of-box experience with a design similar to the one found in build 4001, albeit with a new wallpaper. Attempting to create a new user account will cause the OOBE to crash, skipping the final stage entirely and sending the user to the desktop with the default Administrator account.

New features

 * Nearly all references to Windows XP have been removed by this point, most notably the logo shown within the About Windows dialog box, which was replaced by the Longhorn logo, showing the copyright date, 2006 (assumably a typo of 2003). Windows XP is still referenced in the boot/safe to shutdown screen, in the Help and Support Center, in the Windows XP Tour, and in Windows Messenger.
 * Tiles have been modified slightly, such as the slide show tile having a smaller slideshow and the search the internet tile being a button only rather than including a search box alongside it.

Installation

 * Setup will take longer to boot from the installation media when the computer is set to SATA mode. It is recommended to use an ATAPI CD-ROM drive with a SCSI or IDE hard disk drive.
 * The EULA mistakenly defines the system as pre-release code for Whistler.
 * USB devices may not work during setup when the computer is set to SATA mode.
 * On some machines that use IDE emulation, setup will hang when reading from the installation media.
 * Unpartitioned drives cannot be selected for installation in the setup. To setup from a hard drive without any partitions, select the disk that Windows will be installed on. Otherwise, you can partition and format a drive outside of this build's setup.
 * Many drivers aren't installed by default during the hardware portion of setup and have to be installed manually.
 * The OOBE will crash upon attempting to create a user account.

Desktop Compositing Engine
Desktop Compositing Engine requires either compatible hardware or VMware Workstation 6.5.x to work, otherwise the video driver will crash and force the user to hard reset the machine.

Control Panel
Display Properties mentions the Luna theme as the Plex theme.

Miscellaneous

 * The  banner shows 2006 as a copyright date (possibly a typo). This quirk was fixed in build 4011.