Detecting Media Format Support of the Media Renderer with Microsoft DirectShow Media Streaming is getting popular and feasible because of the higher network bandwidth. The supported media formats also increase rapidly. The end user on the streaming client side seldom realizes that the reason certain media content can not be rendered on the computers is due to the lack of the corresponding decoder. As a result, the ability to determine the media contents that streaming client can support and how to negotiate with streaming servers for compatible media format will ease the use of streaming. This paper proposes a solution based on Microsoft DirectShow which can test if the specified media format, for example, MPEG-1, MPEG-2, MPEG-2 transport stream etc, is supported. By obtaining this information, streaming servers can trans-code media contents to the specified media format that the streaming clients supported. Also, this information can be used to offer other streaming mechanism such as UPnP.