Trust me, if you are not into DVD Ripping you can safely remove the following: * Windows Media 7 [version 7.1.0.3055] * Windows Media 8 [version 8.0.0.371] * Windows Media 9 VCM [version 9.0.1.369] * MS MPEG-4 [version 4.1.0.3927] [Encoding] WMP10 can play WMV7, WMV8 and WMV9 and also WMVA (WMV9 Advanced Profile). Nowadays, you don't need to use the old MS MPEG-4, you use the new WMV9 instead. If you are into *ivX ripping, having the following is fine: * DivX Pro [version 5.1.1] [Decoding] * DivX Pro [version 5.1.1] [Encoding] * XviD 1.0.0.0 RC2 [2004-02-07] [Decoding] * XviD 1.0.0.0 RC2 [2004-02-07] [Encoding] Otherwise, I only have 3ivxDSDecoder.ax registered and 3ivx.dll copied to System32 directory.