You receive an error message when you try to play content that is located on a Windows Media Services 4.1 server after you install Windows Media Player 11

After you install Windows Media Player 11, you receive the following error message when you try to play content that is located on a Windows Media Services 4.1 server:

Windows Media Services 4.1 supports only the Microsoft Media Server (MMS) protocol and the Hypertext Transfer Protocol (HTTP) protocol. Windows Media Player 9 adds support for the Real Time Streaming Protocol (RTSP) protocol. However, support for the MMS protocol began to be deprecated in Windows Media Player 9. Windows Media Player 11 does not support the MMS protocol. Therefore, if the HTTP protocol is not enabled on the Windows Media Services 4.1 server, Windows Media Player 11 cannot connect to the server.

To resolve this problem, upgrade to Windows Media Services 9 Series. Windows Media Services 9 Series is available as part of Microsoft Windows Server 2003. To select the correct version for your business needs, see the product documentation.

Windows Media Services 9 Series has support for RTSP-enabled clients. Windows Media Services 9 Series allows for legacy clients to connect by using the MMS protocol.

If you cannot upgrade, you must enable the HTTP protocol for Windows Media Services 4.1. To do this, follow these steps:

1. Open the Windows Media administration console. To do this, click Start, click Programs, click Administrative Tools, and then click Windows Media.
2. In the navigation pane, click Server Properties under Configure Server.
3. In the topic pane, click the HTTP Streaming and Distribution tab.
4. Click one of the following, depending on the type of distribution that you want to use:
   • Windows Media Unicast
   • Windows Media Station
5. Click Apply, and then close Windows Media Administrator.
6. Restart the server.

Notice that Windows Media Player 11 can now connect by using HTTP. Additionally, Windows Media Player 11 can play content from the server.

When you enable HTTP, a port conflict with IIS may cause an error if Microsoft Internet Information Services (IIS) is installed on the same server as Windows Media Services. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

This behavior is by design.

MMS is used to represent both a protocol and a URL moniker. The MMS URL moniker (mms://) is still typically used by Web content authors to connect the client to the server. When the moniker is used in this form, the moniker allows for the client to automatically select among the supported protocols. When MMS is explicitly referenced as a protocol, the transport is specified as part of the URL moniker (for example, mmsu:// or mmst://). For more information about protocols and protocol rollover, see the product documentation.