Windows Vista build 6001.16637

Windows Vista build 6001.16637 is a Service Pack 1 beta build of Windows Vista. It was shared by the Chinese community BetaWorld on 17 November 2022, along with the Pan-European release of Windows 98 build 1577, Windows 8 build 9200.16456 (win8_gdr_soc_intel) and Windows 8.1 build 9468.

Prior to its publication, the build was found by BetaWorld members WoodEar85 and LeakerLand.S on 26 July 2022, where it was contained within a Hewlett-Packard "FREd" installation package, which is speculated to have been used for testing PXE boot functionalities.

Included applications and utilities
This build's Preinstallation Environment image contains several internal Hewlett-Packard utilities as well as a modified copy of the Firefox web browser (version 2.0.0.4), 7-Zip, the Perl scripting language (version 5.8.7), the Mono framework (version 2.2) and an unregistered version of the TextPad text editor (version 4.7.3). The boot image also contains a private compile of the Matrox G200e video driver. The default WinPE background has also been replaced with a blue and gray background with the phrase "HP Diagnostics" at the top and a low-quality JPEG featuring a logo of HP's ISS supply chain engineering division at the bottom.

By default, the boot image's startup script is programmed to automatically install several device drivers and change the resolution to 1024x768 pixels in both 16- and 32-bit color modes, followed by it running the HP AppServer Discovery client (version 1.0.2) on an infinite loop (until an  batch file is created, resulting in several PRISM-related scripts executing afterwards), which attempts to locate a nonexistent ReMUS AppServer within a local network.