Windows 10 build 18991
| Build of Windows 10 May 2020 Update | |
| OS family | Windows 10 (NT 10.0) |
|---|---|
| Version number | 10.0 |
| Build number | 18991 |
| Build revision | 1000 |
Windows 10 build 18991 is an unleaked build of Windows 10 May 2020 Update. An issue related to this build was posted to GitHub by different Microsoft employees on 25 September 2019.[1]