Xbox One can't find MS Surface 2 on windows media player.

The Xbox (and other media devices) don't access your media files directly. Instead they use something called DLNA, which requires your PC to have indexed your media library.

Then only the index is read by the Xbox (or other media players), and according to that index, you choose the files to play.

If you moved files around, or the index became corrupted, the Xbox can't find the media files anymore.

Please start the Windows Media player on your PC, and check that in that Media Player library, your media files are shown and are working correctly.

If the Media Player can't locate your media, the Xbox 360 can't get to the media as well.

I am using the windows surface 2 RT tablet is it on that yet because I can't find it in the store

I am using the same MS account on all my devices. Alphajax runs fine on my WP8, my desktop PC running Windows 8.1, my Surface Pro 2. It's only not working on my personal Surface 2 running Windows RT 8.1. Yes, I have launched Windows Store, Xbox Games, and
done everything I can think of to get this to work. I only have my one personal MS account on all these devices.

From your pc open .mkv in windows media player and choose play to..xboxone... works, but qualety is real bad.

Lets hope MS gives us an xbox network media player APP

While you can't use Media Center with Windows 10 (as Windows 10 doesn't have Media Center anymore), you can still stream music, videos and pictures to your Xbox 360 via DLNA.

To set that up, start the Windows Media Player on your Windows 10 PC, and make sure the Media Player has access to your media files. Usually, Media Player looks for that under "Users\[YOUR USERNAME HERE]\[Pictures | Music | Videos]"

If you use different folders or drives for your media library, you need to add those folders and drives to the Media Player's library.

If your media shows up in the Media Player window, you need to turn on Media Sharing on the Windows 10 PC.

Open the start menu, and type "Control" to find the Control Panel.

In the Control Panel, type in the upper right corner "Media"

Under "Network and Sharing Center" should be a link to the "Media Streaming Options".

If necessary, enable Media Streaming and make sure your Xbox 360 is running.

You should then see the Xbox 360 in the list of available devices. Allow the Xbox 360 to access your PC's Media Library.

Now, on your Xbox 360, start the Music Player, Photo Viewer or Video player, and as source choose your PC from the list.

You should then see the media that your PC shares to your local network.