The Slingbox Player requires Windows codecs to play.  You may get this or a similar error message:  [Advanced users: the error code is 0x8004025f.]  You must install Windows Media decoders prior to using SlingPlayer. Please run Windows Media Player or download the decoders.  These can be added to the above versions of windows by following the directions below:

The Media Feature Pack for Windows 7 N or Windows 7 KN will install Media Player and related technologies on a computer running Windows 7 N or Windows 7 KN editions, or these editions with Service Pack 1.

Visit the following Website to download the Windows Media Feature Pack for Windows 7 N with Service Pack 1 and Windows 7 KN with Service Pack 1 :

Media Feature Pack for Windows 7 N with Service Pack 1 and Windows 7 KN with Service Pack 1 (KB968211) 
For further information, please see the Knowledge Base article numberKB968212 or related KB article KB968211. This download is available to customers running genuine Microsoft Windows. 
http://www.microsoft.com/downloads/en/details.aspx?FamilyID=31017ed3-166a-4c75-b90c-a6cef9b414c4 
Download x86 Edition -> Windows6.1-KB968211-x86-RefreshPkg.msu 
Download x64 Edition -> Windows6.1-KB968211-x64-RefreshPkg.msu

Windows 7 N and Windows 7 KN editions include the same functionality as Windows 7, except that these versions of Windows do not include Windows Media Player, and related technologies. End-user customers can enable the media functionality to work properly by installing the Windows Media Feature Pack for Windows 7 N and Windows 7 KN.

Supported Operating Systems: N- and KN-Editions of Windows 7 Starter, Windows 7 Home Premium, Windows 7 Professional, Windows 7 Enterprise and Windows 7 Ultimate.