The quickest way to get a dark interface without installing software is using the High Contrast accessibility feature. Microsoft Learn Activation Swipe from the right (or press Change PC settings Ease of Access High contrast Toggle the switch to and select a theme like High Contrast Black
This is the closest you will ever get to a modern . dark theme for windows 8.1
Always create a System Restore point before patching system files. If something goes wrong, you can revert your system to its previous state. The quickest way to get a dark interface
While not strictly "Windows," many users seeking a dark theme for Windows 8.1 enjoy the "Yosemite Black" or "Mojave Dark" ports. These themes dark theme for windows 8.1