Windows 10 Super Lite 500mb -

It allows you to toggle off the "Shell" (Start Menu/Taskbar) and run in a "Pro Mode" that looks like a command line but runs GUI apps, saving 150MB of RAM instantly.

Application denied. Notepad.exe is unnecessary. Windows 10 Super Lite 500mb

If you need a lightweight OS for an old computer, there are safer, legal alternatives to Windows 10 Super Lite: It allows you to toggle off the "Shell"

This article explores what these versions are, how they achieve such small sizes, and the dangers of using them. there are safer