It seems to work fine for me on both W7 and W10 - I tried different templates etc.
Please make sure you have this registry changes in the right path Enabling HTML5 in the Windows .net Player
You can also try to add it here:
HKEY_Current_User\SOFTWARE\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BROWSER_EMULATION
Of course make sure that IE11 is actually installed