Hi,
To embed a youtube video, just copy the code from the "Embed" box—you can find it in the "About This Video" box when you're watching the video. Once you've copied the code, you can paste it in the HTML version of the description by switching the HTML editor to display HTML.
If you want to authorize the extension wmv in the files section, you should go in the configuration of HikaShop under the tab Files. There you can add to the "Allowed files" option the wmv extension.
