Windows 8 build 7861
| Build of Windows 8 | |
 | |
| OS family | Windows NT |
|---|---|
| Version number | 6.1 |
| Build number | 7861 |
| Build revision | 0 |
| Architecture | x64 |
| Build lab | fbl_grfx_dev1 |
| Compiled on | 2010-10-13 |
| Expiration date | |
| Timebomb | 2011-02-05 (+115 days) |
| About dialog | |
Windows 8 build 7861 is a build of Windows 8. It was shared on 11 October 2024, along with its server counterpart from the fbl_core1_hyp_dev lab.
As of 2024, this is the last known build to bear the 6.1 kernel version.
Editions and keys[edit | edit source]
| Edition / SKU | Key |
|---|---|
| Home Basic | YGFVB-QTFXQ-3H233-PTWTJ-YRYRV |
| Home Premium | RHPQ2-RMFJH-74XYM-BH4JX-XM76F |
| Professional | HYF8J-CVRMY-CM74G-RPHKF-PW487 |
| Ultimate | D4F6K-QK3RD-TMVMJ-BBMRX-3MBMV |
New features and changes[edit | edit source]
Interface[edit | edit source]
The Windows Aero visual style has been changed slightly and now features smaller caption buttons in certain dialogs.
Leak prevention[edit | edit source]
A near-final implementation of the Windows Fingerprinting Service has been added through the addition of a dedicated fingerprinting blob in the system, displayed on the desktop watermark and the Version Reporter Applet by shell library shell32.dll. The fingerprint is directly appended at the end of the BuildLab string (queried from registry key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion) in the form of a build hash (officially named the "EULA hash"), computed by splitting the WFS blob into 8 arrays of 16 bytes and XORing each of the 16 bytes together. The EULA hash can then be derived in order to source build leaks to existing Microsoft affiliates; the visibility of the EULA hash and the confidentiality warnings depend on the presence of certain compiler flags.
Fingerprinting data is now stored in the registry key HKLM\SYSTEM\WPA\478C035F-04BC-48C7-B324-2462D786DAD7-5P-9. The registry key must exist in the Windows install, or the operating system will either refuse to boot or non-deterministically bugcheck with codes KERNEL_SECURITY_CHECK_FAILURE (during boot) or CRITICAL_STRUCTURE_CORRUPTION (if the periodic WFS check during runtime fails). Furthermore, most parts of the fingerprint data are now encrypted, and therefore require reverse engineering efforts to decode and extract the relevant information.
Gallery[edit | edit source]
Interface[edit | edit source]
Boot screen
Start screen
Search charms
Charms bar
