Is there a PowerShell command that will retrieve the Windows "codename"?
10.0.19042 has a "codename" of "20H2".
Is there a Get-CimInstance class (or other command) that contains "20H2"?
PS C:\> $PSVersionTable.PSVersion.ToString()
7.3.2
Starting with 20H2, you can find this value in the registry key Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion In the DisplayVersion value.
(Get-Item "HKLM:SOFTWARE\Microsoft\Windows NT\CurrentVersion").GetValue('DisplayVersion')