Downloading Windows 10 21H2 wrong build

I'm trying to download Windows 10 21H2, which carries the build number 19044.

However, when I try to download Windows 10 via microsoft's website, it's downloading version 10.0.19041.1288, which is 20H1.

How can I download 19043 or higher?

This is a known issue with Windows 10 WIM images/ISOs. Multiple releases share the same operating system core. For example, I'm on 21H1 (19043) yet my ntoskrnl.exe still has version 19041.

Microsoft also has a KB article on this. Unfortunately, it is somewhat out of date.

The "enablement packages" are:

• 20H2: Package_for_KB4562830
• 21H1: Package_for_KB5000736
• 21H2: Package_for_KB5003791 (indeed present in the image)

You can find links to these KB articles in the release information page.

To check the packages, you have to mount the image in an (empty) folder:

dism /Mount-Wim /WimFile:D:\sources\install.wim /index:1 /MountDir:C:\Path\To\Mount\Dir /ReadOnly

You can then use the following command to list the packages:

dism /Image:C:\Path\To\Mount\Dir /Get-Packages

After you're done, don't forget to unmount the image:

dism /Unmount-Wim /MountDir:C:\Path\To\Mount\Dir /discard