The Windows themes you implement on a desktop or server can be changed using the integrated PowerShell utility. ... Create the variables for the desktop or server name and the theme you want to use.

This post describes the various ways to change Theme in Windows 11/10 You can do so via Command Prompt, PowerShell, Control Panel, Explorer, etc.

The interface in the final versions of Windows .NET Server—Standard and Enterprise—resembles that of XP and uses the Classic theme. There's an XP-like taskbar to navigate to programs.

Windows 10 also moves the location of theme customization from the old-style Control Panel. You'll find them in Settings > Personalization > Themes, as shown here.