Windows 8.1 Playing videos

I don't think this is a serviio problem. It has to do with media playback. In Windows 8.0 this worked perfectly:
In Windows Explorer I click on the Serviio device. I see a list of folders. I navigate to the video I want, double-click on the file and it starts to play immediately. After upgrading to windows 8.1 the video doesn't play immediately, it appears to get downloaded first and then it plays.
I'd like the video to start playing immediately like it did before the Windows 8.1 upgrade. Does anyone know how to stop this behavior?
Thanks very much
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I'm using the latest version of the K-Lite Code pack with Windows Media Player but it happens with other players too.
In Windows Explorer I click on the Serviio device. I see a list of folders. I navigate to the video I want, double-click on the file and it starts to play immediately. After upgrading to windows 8.1 the video doesn't play immediately, it appears to get downloaded first and then it plays.
I'd like the video to start playing immediately like it did before the Windows 8.1 upgrade. Does anyone know how to stop this behavior?
Thanks very much
----
I'm using the latest version of the K-Lite Code pack with Windows Media Player but it happens with other players too.