No reboot is typically required. Your Windows 11 remains on DirectX 12 – you are legacy files, not downgrading.
The short answer is yes , but with nuance. This 4,000-word guide will explain everything you need to know—from installation quirks and compatibility errors to performance tweaks and workarounds.
Installing is not a complex hack; it is a supported feature buried under layers of translation. You do not need to downgrade your OS or run a virtual machine. With the methods outlined above—using Microsoft's default translation layer, optionally adding DXVK for stubborn titles, and tweaking compatibility settings—you can play every classic DX9 game perfectly.