You're referring to "Windows Sonic for Headphones"?
Press the Windows Key + S and type sound, click on Sound Control Panel, right click on your playback device and select properties, select the Spatial Sound tab, select Windows Sonic for Headphones and check Turn on 7.1 virtual surround sound. If that doesn't work or the option is not there, then it would be safe to assume the feature is broken or has been pulled.