The Windows 10 Fall Creators Update comes on many systems without High Efficiency Video Codec (HEVC, also known as H.265) support. After the update has been installed, users have to download the codec from the Microsoft Store if they want to view HEVC content.
Once the Windows 10 Fall Creators Update is installed, it's no longer possible to play HEVC videos on some systems, because Microsoft no longer ships the HEVC codec with the latest update. Instead users have to download the free 'HEVC Video Extension' from the Microsoft store. The issue can be simply reproduced by trying to to view a HEVC video in the Movies & TV app, according to Heise. Most of the times it will show a blank screen.
After installing the Extension, videos should play fine again. The HEVC Extension supports hardware acceleration through the IGPUs of Intel Skylake, Kab Lake (Refresh) and Coffee Lake chips. Also AMD Radeon RX 400, RX 500, RX Vega 56/64 and Nvidia GTX 1000, GeForce GTX 960 and GeForce 950 GTX graphic cards are able to accelerate HEVC content.
On some systems the HEVC decoder is, for some reason, installed already. Update KB4041994 seems to install the decoder on some systems which means on those systems the 'HEVC Video Extension' doesn't have to be installed from the Microsoft store.
The 'HEVC Video Extension' is not only useful for Windows 10's Movies & TV app, also Netflix 4K HDR streaming requires the codec. To be able to fully enjoy this content, also a up-to-date GPU driver has to be installed.
