Can I play games with a keyboard and a mouse on streaming if the game is only installed on...

Yes but what if I want to use the mouse and keyboard while streaming, I dont want to have to unplug my desktops mouse and keyboard and connect it to my xbox when I have the ability to play from here. Can I play mouse and keyboard supported games through
streaming?

In order to keep an equal and fair multiplayer experience, you can only play with controllers on the Xbox One.

Games that work on the PC as well (like for example Gears of War 4) can be played with keyboard and mouse, but you can only play cooperative multiplayer with console owners that have to use controllers, so mouse and keyboard users don't have an advantage.

These XIM4 or Mayflash devices aren't real mouse and keyboard devices. These devices show themselves as a standard controller to the console, and when you move the mouse, the adaptor "guesses" from the speed you move the mouse, how hard it should push a
simulated controller stick in a certain direction.

These adaptors won't give you the same control as the mouse on a real PC.

When you stream the Xbox game screen to your PC, you can also only use a Xbox controller. Mouse and Keyboard won't work as a game input (you can only use the keyboard to enter text when the virtual keyboard is shown).

There are plans to get Keyboard and mouse working, if there ever is a way to stream the PC screen to the Xbox console.

But currently, if you're playing on the Xbox console, it's controller only (even if the controller is "guesstimated" with mouse and keyboard inputs).

Okay thank you very much, I have one small question when it comes to streaming. If i were to stream an Xbox 360 game from an Xbox One to my Windows PC, would I be able to control that streamed game with my mouse and keyboard as opposed to a controller while
on my Windows PC playing the streamed game?

No, only controller. You can't use mouse and keyboard in this fashion for any games over xbox one streaming.

The Xbox can't be controlled by keyboard and mouse through the Stream mode at all. While it's possible in the Minecraft Bedrock Edition to use Keyboard and mouse, all other games don't accept keyboard and mouse input at all.

You might have to try Minecraft, if you can control it via Keyboard and mouse while streaming to your PC.

Yeah, I'm not competitive enough to really care about Keyboard and Mouse support, and when I play it's usually not in a position where keyboard and mouse are easy to use. Only time I play at a desk is when I'm streaming, which isn't often, and then I'm
using it to control the stream, chat, etc.

As far as it goes, I think the more options the better. Keyboard and mouse support can do a lot to making games, on whatever platform, more accessible, where with KB+Mouse usually comes the ability to re-bind buttons, and that can be night and day for people
with accessibility needs. It's not always easy but can make all the difference.