Microsoft may be planning to push the first Windows 10 21H1 aka Version 2104 and Windows 10X preview builds to insiders this week, we reported via a leak. Now, the same source has confirmed that the Build 20150 may be the first preview build for Windows 10 21H1 and may be out today.

The tweet posted by ALumia also has an image that shows that Microsoft will push ISOs for the Build 20150. This is a bit surprising given this is the very first preview build from the new “Iron” branch.

Windows 10 21H1 is supposed to bring many Start menu, File Explorer, context menu changes, and updated versions of apps like Calendar, Photos, Microsoft Edge, and others. Read more about new Windows 10 21H1 features and changes by clicking here.