timppu: By the way, is all this still relevant or even possible on Windows 11
It
shouldn't be relevant at all, in theory all you need is already included in the OS and in the driver, but sometimes it is relevant anyway :(
In any case there is no harm in running the installer at least once.
Microsoft tends to remove certain components from Windows installations once in a while. If you upgrade your system, you won't notice, but sometimes after a fresh "Windows XYZ Service Pack 99987" installation, components are missing that were present in a earlier version. And if devs rely on these components being present, the software won't work on that new version.
.. and always keep a Windows 8 version of dinput.dll (DirectInput) at hand. DirectInput was changed with Windows 10, some older games crash at startup when certain DirectInput controllers are connected. In that case copy this dll into the game directory (or disconnect the controller). Yes, I am looking at Telltale games here, they never bothered to upgrade their games, not even before they went bankrupt.