Operating System Beta, etc. Wiki
Windows 10 Manganese
Architecture x86, x64, ARM64
SKUs Home
Home China
Home N
Home Single Language
Pro N
Pro Single Language
Pro China Only
Pro Education
Pro Education N
Pro for Workstations
Pro N for Workstations
Education N
Enterprise Evaluation
Enterprise G
Enterprise G N
Enterprise multi-session
Enterprise N
Enterprise N Evaluation
IoT Enterprise
BIOS date 2020-05-30 (Compiled)
Key This build accepts Windows 10 license keys.
Timebomb 2020-07-31 (+62 days)

Windows 10 Build 19640 is is the twenty-first Insider Preview Build of Manganese. It was released on 2020-06-03 to all Insiders in the fast ring.


  • If the users's download folder is synced to a cloud provider, it disables the option to have Storage Sense automatically clear your Downloads folder on a cycle.
  • Login logic was updated, so if the user has their PC set up so they have to type their username while logging in, typing a space at the beginning of your username will not generate an error anymore.

Bugs and quirks

  • Both the Documents and Downloads sections under privacy settings have a broken icon, and a rectangle is shown in their place.
  • Taskbar preview thumbnails do not render consistently in this build (showing a blank area).
  • Some devices may BSOD upon resuming from hibernate if booting from eMMC storage.