Windows Longhorn build 4091 (main)
| Build of Windows Longhorn | |
 | |
| OS family | Windows NT |
|---|---|
| Version number | 6.0 |
| Build number | 4091 |
| Build lab | main |
| Compiled on | 2004-07-26 |
Windows Longhorn build 4091 (main) is an unleaked Milestone 8 build of Windows Longhorn. The XImage from this build was posted by ReflectiaX in 2020.[1] The installation files for this build were shown in a screenshot posted to Neowin thread[2] on 12 August 2004 - although in that thread, the screenshot was accused of being fake, the file list shown includes changes not seen publicly until build 4093, which wasn't even compiled yet on that date, indirectly confirming the screenshot's authenticity.