For gamers, Windows 98 was a great operating system in beloved memories. Many great games were played on that OS for years, and people kept making the emulators even after decades to keep the good old feeling. With this idea in mind, Digital Foundry found a way to run Windows 98 on Xbox Series X. You will need RetroArch, DOSBox Pure and a copy of Windows 98 on the device. 

You can install Windows 98 on your Xbox Series X by either activating developer mode for a cost, or by following a more risky way for a side-install which might get your Xbox Live account banned. 

Digital Foundry says that the experience is actually quite nice. There is also a small issue with mouse detection which is not resolved, so you will still need a controller to move the cursor around. In any case, using a PC is still easier but if you do not have a PC at your disposal, you still have chance on your Xbox.