Hi there, Basically, the media player is an ActiveX control which is installed and run at the client side, and the information about the client provided by the ASP.NET is not much, it is normally taken from the header of the request sent by the client browser. And this information does not contain any information about a specific ActiveX control installed on the client machine. So to detect if the player ( or an ActiveX control in general ) is installed at the client side or detect the version of the player, you basically use the client side script (runs at the client side) like javascript or vbscript to do the trick.