Summary
Technical Level: Basic
Applies to: Windows 8.1 with Update 1, also WindowsRT 8.1 with Update 1
If your device supports DLNA “Play To” using the classic desktop/explorer/libraries functionality, it should work transparently with Modern Apps that support the Play contract (feature) after installing the April 8, 2014 updates to Windows 8.1. The Photos App in Windows 8.1 does NOT support Play To.
Details
Note: As of April 8, 2014, Microsoft has released an Update to Windows 8.1 that makes it unnecessary to perform any registry edits to enable a DLNA Digital Media Renderer (DMR) to work with Modern Apps on the Start Screen. Devices will no longer appear as "uncertified" when Play is selected within an individual app (but if not certified will appear as such in the PC and Devices menu).
Note that this change only applies to Windows 8.1 Update 1, and will not be rolled out for 8.0. Windows 8.1 is a free upgrade and Update 1 is a mandatory update.
Background
A little history: In Windows 7, Microsoft introduced Play To which used the DLNA spec to let me send media from my computer to a DLNA DMR. I had so so results with my 2009 Samsung TV due to poor transcoding support, but great results with my WDTV Live Hub and my SONOS speakers. The so-so experience on my TV and the not wonderful experience on other device by many many people caused Microsoft to rethink their strategy for Windows 8 and come up with a more intensive certification process for devices to “insure” a good experience. This translated into a restrictive policy for Windows 8 Start Screen/Metro/Modern UI Apps where only MS certified devices would appear in an applications Settings: Devices menu. In Windows 8, a workaround is available that requires a registry entry for each device you wish to enable for Play To support for Modern UI Apps. In Windows 8.1, a global registry key was added so that individual keys were no longer needed.
In Update 1, released April 8, 2014, no modification is needed, as Microsoft has again re-examined the need for a restriction on Play devices. If your device works as a Play To device in the legacy Windows File Explorer environment, it should work equally well as a Play device from Charms, Devices Play if the application you are using supports the Play contract. Note that the end user experience will vary as some devices do not properly support all the necessary DLNA specifications.
To check if your device is certified for Windows:
1. Click or tap the Settings Charm on the Start Screen
2. Select Change PC Settings
3. Select PC & Devices
4. Select Devices
5. Verify that your device is listed (the example below shows the TV that is Not Windows Certified as present in the list)
6. If the Device is not present, use Add Device to attempt to add the device to the list
Next Step: Verify Legacy DLNA “Play To” Support
1. To do this, right click a supported media file in a classic library and verify the Play To menu appears
2. Next, verify that you can successfully send to your target device and it plays the media you selected.
a. To do this, right click a supported media file in a classic library and verify the Play To menu appears and that you can successfully send to your target device and it plays the media you selected.
Use Modern Apps with Play Support Automatically
Once you have verified that your DLNA device supports PlayTo, that device should work with any Modern App that supports the Play Contract. Note that not all apps include this capability. If Play is supported, your devices will appear in the Play menu after you select Charms, Devices, Play. Devices shown here will not have an uncertified designation. Below is a screen capture showing the Play experience inside a third party photo app. As you can see, the TV is listed, but not designated Uncertified.
