Windows Longhorn Post-Reset

Windows Longhorn was the pre-release codename for Windows Vista and was the successor to Windows XP and Windows Server 2003 (built from NT 5.2 codebase). Development on the OS started in May 2001 and went through two unique development cycles separated by a development reset in 2004. The reset occurred as Microsoft's development staff had lost focus on the project as a whole and what was required to be done in order to bring it to market. Features were being written into the OS at an alarming rate with a significant lack of QA or vision of true requirement. This combined with Microsoft's trustworthy computing initiatives caused the reset.

Several features of Longhorn planned that were actually shipped include the glass replicating Aero theme (which followed the Slate and Jade themes from earlier builds), along with the Windows Sidebar - although this was shipped as a standalone utility where as most builds (at least in pre-reset) shipped this as part of explorer.exe. Numerous improvements to the Windows Explorer, along with an updated Internet Explorer 7, Windows Media Player 11, instant search, new 3-d games and other items made it into the final version of Windows Vista.

Release notes

Windows Longhorn existed as a continuation of the Windows 2003 codebase although after build 4094 development was reset; restarted from scratch as the original Longhorn builds were growing in complication (described as 'a mess') and Microsoft introduced a new focus on security. These are the post-reset builds.

Product type
Release date
User interface
Download count
540 (214 for release)


Download name Version Language Architecture File size Downloads
Windows Longhorn (6.0.5048.0) (beta1) 6.0.5048 Prerelease English 841.68MB 30
Windows Longhorn (6.0.5048.0) (x64 beta1) 6.0.5048 Prerelease English 1.25GB 9
Windows Longhorn (6.0.5112.0) (beta1) 6.0.5112 Prerelease English 1.56GB 7
Windows Longhorn (6.0.5112.0) (x64 beta1) 6.0.5112 Prerelease English 1.65GB 58
Windows Longhorn (6.0.5219.0) (beta2) 6.0.5219 Prerelease English 1.89GB 17
Windows Longhorn (6.0.5231.0) (beta2) 6.0.5231 Prerelease English 2.02GB 7
Windows Longhorn (6.0.5231.2) (x64 beta2) 6.0.5231 Prerelease English 2.55GB 1
Windows Longhorn (6.0.5259.0) (beta2) 6.0.5259 Prerelease English 1.61GB 13
Windows Longhorn (6.0.5270.9) (beta2) 6.0.5270.9 Prerelease English 1.97GB 6
Windows Longhorn (6.0.5270.9) (x64 beta2) 6.0.5270 Prerelease English 2.45GB 3
Windows Longhorn (6.0.5308.17) (beta2) 6.0.5308.17 Prerelease English 2.73GB 0
Windows Longhorn (6.0.5308.17) (x64 beta2) 6.0.5308.17 Prerelease English 3.58GB 5
Windows Longhorn (6.0.5308.60) (beta2) 6.0.5308 Prerelease English 2.19GB 0
Windows Longhorn (6.0.5342.2) (beta2) 6.0.5342.2 Prerelease English 2.81GB 1
Windows Longhorn (6.0.5365.8) (beta2) 6.0.5365.8 Prerelease English 3.05GB 31
Windows Longhorn (6.0.5381.1) (beta2) 6.0.5381.1 Prerelease English 3.27GB 11
Windows Longhorn (6.0.5384.4) (beta2) 6.0.5384.4 Prerelease English 3.19GB 3
Windows Longhorn (6.0.5384.4) (x64 beta2) 6.0.5384.4 Prerelease English 4.05GB 0
Windows Longhorn (6.0.5456.5) (beta2) 6.0.5456.5 Prerelease English 2.53GB 1
Windows Longhorn (6.0.5456.5) (x64 beta2) 6.0.5456 Prerelease English 3.28GB 0
Windows Longhorn (6.0.5472.5) (beta2) 6.0.5472 Prerelease English 2.59GB 0
Windows Longhorn (6.0.5536.16385) (rc1) 6.0.5536.16385 Prerelease English 2.59GB 0
Windows Longhorn (6.0.5552.16384) (rc1) 6.0.5552.16384 Prerelease English 2.6GB 0
Windows Longhorn (6.0.5600.16384) (rc1) 6.0.5600.16384 Prerelease English 2.53GB 0
Windows Longhorn (6.0.5600.16384) (x64 rc1) 6.0.5600 Prerelease English 3.59GB 0
Windows Longhorn (6.0.5728.16387) (rc1) 6.0.5728 Prerelease English 2.58GB 0
Windows Longhorn (6.0.5728.16387) (x64 rc1) 6.0.5728 Prerelease English 3.58GB 2
Windows Longhorn (6.0.5744.16384) (rc2) 6.0.5744 Prerelease English 2.5GB 0
Windows Longhorn (6.0.5744.16384) (x64 rc2) 6.0.5744.13684 Prerelease English 3.56GB 3
Windows Longhorn (6.0.5754.1) (rc2) 6.0.5754 Prerelease English 2.5GB 0
Windows Longhorn (6.0.5840.16384) (rc2) 6.0.5840.16384 Prerelease English 2.51GB 6


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