The Windows 10 May 2021 Update[1] (codenamed "21H1"[2]) is the eleventh major update to Windows 10.
It carries the build number 10.0.19043.
The first preview was released to Insiders who opted in to Beta Channel on February 17, 2021.
[3] The update began rolling out on May 18, 2021.
[4] Notable changes in the May 2021 Update include:[5] The update has reached end of service on December 13, 2022.