How to optimize Windows for gaming?

I have a low-end PC and I was told I can optimize the operating system to run with the maximum FPS possible, even without a graphics card. They said I need to disable some services, tweak the power mode and lower some in‑game settings. But what exactly do I need to do? Which services do I need to disable? How should I set the power mode? I installed Windows in game mode. Doesn’t that already do all of this automatically? Help.

Follow this video
https://m.youtube.com/watch?v=4CLhApQp0g0
On the laptop, performance is higher when you select the high power mode.
You can also disable Windows Defender if it’s not necessary.